`tmuxp load` AssertionError or loads session only partially

[mirosval]

Step 1: Provide a summary of your problem

Previously working setup now only opens the first window when loading a new session using tmuxp load

Step 2: Provide tmuxp details

`tmuxp debug-info`

-------------------------
environment:
	dist: macOS-13.1-arm64-arm-64bit
	arch: arm64
	uname: Darwin; REDACTED.local; 22.2.0
	version: Darwin Kernel Version 22.2.0: Fri Nov 11 02:03:51 PST 2022; root:xnu-8792.61.2~4/RELEASE_ARM64_T6000
-------------------------
python version: 3.11.1 (main, Dec 23 2022, 09:28:24) [Clang 14.0.0 (clang-1400.0.29.202)]
system PATH: REDACTED
tmux version: 3.3
libtmux version: 0.18.2
tmuxp version: 1.24.0
tmux path: /opt/homebrew/bin/tmux
tmuxp path: /opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp
shell: /opt/homebrew/bin/zsh
-------------------------
tmux sessions:
	dotfiles: 1 windows (created Tue Jan  3 12:56:29 2023) (attached)
	tracking: 1 windows (created Wed Jan  4 11:54:03 2023)

tmux windows:
	1: dotfiles* (2 panes) [426x85] [layout fc8c,426x85,0,0{212x85,0,0,1,213x85,213,0,2}] @1 (active)

tmux panes:
	1: [212x85] [history 21/50000, 447700 bytes] %1
	2: [213x85] [history 1464/50000, 718639 bytes] %2 (active)

tmux global options:
	@net_speed_interfaces en0
	@plugin jimeh/tmux-themepack
	@powerline-color-activity-1 colour75
	@powerline-color-black-1 black
	@powerline-color-grey-1 colour233
	@powerline-color-grey-2 colour235
	@powerline-color-grey-3 colour238
	@powerline-color-grey-4 colour240
	@powerline-color-grey-5 colour243
	@powerline-color-grey-6 colour245
	@powerline-color-main-1 colour39
	@powerline-color-main-2 colour81
	@powerline-color-main-3 colour75
	@powerline-status-bg colour233
	@powerline-status-fg colour240
	@powerline-status-left-area-left-bg colour39
	@powerline-status-left-area-left-fg colour233
	@powerline-status-left-area-middle-bg colour240
	@powerline-status-left-area-middle-fg colour233
	@powerline-status-left-area-right-bg colour235
	@powerline-status-left-area-right-fg colour240
	@powerline-status-left-bg colour233
	@powerline-status-left-fg colour243
	@powerline-status-right-area-left-bg colour235
	@powerline-status-right-area-left-fg colour240
	@powerline-status-right-area-middle-bg colour240
	@powerline-status-right-area-middle-fg colour233
	@powerline-status-right-area-right-bg colour245
	@powerline-status-right-area-right-fg colour233
	@powerline-status-right-bg colour233
	@powerline-status-right-fg colour243
	@resurrect-restore-script-path /Users/mirosval/.tmux/plugins/tmux-resurrect/scripts/restore.sh
	@resurrect-save-script-path /Users/mirosval/.tmux/plugins/tmux-resurrect/scripts/save.sh
	@resurrect-strategy-irb default_strategy
	@resurrect-strategy-mosh-client default_strategy
	@resurrect-strategy-nvim session
	@resurrect-strategy-vim session
	@theme-clock-mode-colour colour39
	@theme-clock-mode-style 24
	@theme-display-panes-active-colour colour245
	@theme-display-panes-colour colour233
	@theme-message-bg colour39
	@theme-message-command-bg colour39
	@theme-message-command-fg black
	@theme-message-fg black
	@theme-mode-bg colour39
	@theme-mode-fg black
	@theme-pane-active-border-bg default
	@theme-pane-active-border-fg colour39
	@theme-pane-border-bg default
	@theme-pane-border-fg colour238
	@theme-status-bg colour233
	@theme-status-fg colour240
	@theme-status-interval 1
	@theme-status-justify centre
	@theme-status-left "#[fg=colour233,bg=colour39,bold] #S #[fg=colour39,bg=colour240,nobold]#[fg=colour233,bg=colour240] #(whoami) #[fg=colour240,bg=colour235]#[fg=colour240,bg=colour235] #I:#P #[fg=colour235,bg=colour233,nobold]"
	@theme-status-left-bg colour233
	@theme-status-left-fg colour243
	@theme-status-left-length 40
	@theme-status-left-prefix ''
	@theme-status-left-suffix ''
	@theme-status-right "#[fg=colour235,bg=colour233]#[fg=colour240,bg=colour235] %H:%M:%S #[fg=colour240,bg=colour235]#[fg=colour233,bg=colour240] %d-%b-%y #[fg=colour245,bg=colour240]#[fg=colour233,bg=colour245,bold] #H "
	@theme-status-right-bg colour233
	@theme-status-right-fg colour243
	@theme-status-right-length 150
	@theme-status-right-prefix ''
	@theme-status-right-suffix ''
	@theme-window-status-activity-bg colour233
	@theme-window-status-activity-fg colour75
	@theme-window-status-current-bg colour39
	@theme-window-status-current-fg black
	@theme-window-status-current-format " #I:#W#F "
	@theme-window-status-current-prefix ''
	@theme-window-status-current-suffix ''
	@theme-window-status-format " #I:#W#F "
	@theme-window-status-prefix ''
	@theme-window-status-separator ''
	@theme-window-status-suffix ''
	@themepack powerline/block/cyan
	@themepack-status-left-area-left-format "#S"
	@themepack-status-left-area-left-prefix ''
	@themepack-status-left-area-left-suffix ''
	@themepack-status-left-area-middle-format "#(whoami)"
	@themepack-status-left-area-middle-prefix ''
	@themepack-status-left-area-middle-suffix ''
	@themepack-status-left-area-right-format "#I:#P"
	@themepack-status-left-area-right-prefix ''
	@themepack-status-left-area-right-suffix ''
	@themepack-status-right-area-left-format "%H:%M:%S"
	@themepack-status-right-area-left-prefix ''
	@themepack-status-right-area-left-suffix ''
	@themepack-status-right-area-middle-format "%d-%b-%y"
	@themepack-status-right-area-middle-prefix ''
	@themepack-status-right-area-middle-suffix ''
	@themepack-status-right-area-right-format "#H"
	@themepack-status-right-area-right-prefix ''
	@themepack-status-right-area-right-suffix ''
	@themepack-window-status-current-format "#I:#W#F"
	@themepack-window-status-current-prefix ''
	@themepack-window-status-current-suffix ''
	@themepack-window-status-format "#I:#W#F"
	@themepack-window-status-prefix ''
	@themepack-window-status-suffix ''
	activity-action other
	assume-paste-time 1
	base-index 1
	bell-action any
	default-command "reattach-to-user-namespace -l /opt/homebrew/bin/zsh"
	default-shell /opt/homebrew/bin/zsh
	default-size 80x24
	destroy-unattached off
	detach-on-destroy on
	display-panes-active-colour colour245
	display-panes-colour colour233
	display-panes-time 1000
	display-time 4000
	history-limit 50000
	key-table root
	lock-after-time 0
	lock-command "lock -np"
	message-command-style fg=black,bg=colour39
	message-style fg=black,bg=colour39
	mouse on
	prefix C-b
	prefix2 None
	renumber-windows on
	repeat-time 500
	set-titles off
	set-titles-string "#S:#I:#W - \"#T\" #{session_alerts}"
	silence-action other
	status on
	status-bg default
	status-fg default
	status-format[0] "#[align=left range=left #{E:status-left-style}]#[push-default]#{T;=/#{status-left-length}:status-left}#[pop-default]#[norange default]#[list=on align=#{status-justify}]#[list=left-marker]<#[list=right-marker]>#[list=on]#{W:#[range=window|#{window_index} #{E:window-status-style}#{?#{&&:#{window_last_flag},#{!=:#{E:window-status-last-style},default}}, #{E:window-status-last-style},}#{?#{&&:#{window_bell_flag},#{!=:#{E:window-status-bell-style},default}}, #{E:window-status-bell-style},#{?#{&&:#{||:#{window_activity_flag},#{window_silence_flag}},#{!=:#{E:window-status-activity-style},default}}, #{E:window-status-activity-style},}}]#[push-default]#{T:window-status-format}#[pop-default]#[norange default]#{?window_end_flag,,#{window-status-separator}},#[range=window|#{window_index} list=focus #{?#{!=:#{E:window-status-current-style},default},#{E:window-status-current-style},#{E:window-status-style}}#{?#{&&:#{window_last_flag},#{!=:#{E:window-status-last-style},default}}, #{E:window-status-last-style},}#{?#{&&:#{window_bell_flag},#{!=:#{E:window-status-bell-style},default}}, #{E:window-status-bell-style},#{?#{&&:#{||:#{window_activity_flag},#{window_silence_flag}},#{!=:#{E:window-status-activity-style},default}}, #{E:window-status-activity-style},}}]#[push-default]#{T:window-status-current-format}#[pop-default]#[norange list=on default]#{?window_end_flag,,#{window-status-separator}}}#[nolist align=right range=right #{E:status-right-style}]#[push-default]#{T;=/#{status-right-length}:status-right}#[pop-default]#[norange default]"
	status-format[1] "#[align=centre]#{P:#{?pane_active,#[reverse],}#{pane_index}[#{pane_width}x#{pane_height}]#[default] }"
	status-interval 1
	status-justify centre
	status-keys emacs
	status-left "#[fg=colour232,bg=colour255,bold] #S #[fg=colour255,bg=colour250,nobold]#[fg=0,bg=colour250] #(whoami) #[fg=colour250,bg=colour245]#[fg=0,bg=colour245] #I:#P #[fg=colour245,bg=colour240]#[fg=0,bg=colour240] %b %d %H:%M:%S #[fg=colour240,bg=colour233,nobold]"
	status-left-length 100
	status-left-style fg=colour243,bg=colour233
	status-position bottom
	status-right "#[fg=colour245,bg=colour233]#[fg=0,bg=colour245] #(diffmetrik --metric download) #(diffmetrik --metric upload) #[fg=colour250,bg=colour245]#[fg=0,bg=colour250] bat: #(~/.dotfiles/scripts/battery.sh)%%  #[fg=colour255,bg=colour250,bold]#[fg=colour0,bg=colour255]#(~/.dotfiles/scripts/spotify.sh)"
	status-right-length 150
	status-right-style fg=colour243,bg=colour233
	status-style fg=colour240,bg=colour233
	update-environment[0] DISPLAY
	update-environment[1] KRB5CCNAME
	update-environment[2] SSH_ASKPASS
	update-environment[3] SSH_AUTH_SOCK
	update-environment[4] SSH_AGENT_PID
	update-environment[5] SSH_CONNECTION
	update-environment[6] WINDOWID
	update-environment[7] XAUTHORITY
	visual-activity off
	visual-bell off
	visual-silence off
	word-separators "!\"#$%&'()*+,-./:;<=>?@[\\]^`{|}~"

tmux window options:
	cursor-colour none
	cursor-style default
	aggressive-resize on
	allow-passthrough off
	allow-rename off
	alternate-screen on
	automatic-rename on
	automatic-rename-format "#{?pane_in_mode,[tmux],#{pane_current_command}}#{?pane_dead,[dead],}"
	clock-mode-colour colour39
	clock-mode-style 24
	copy-mode-match-style bg=cyan,fg=black
	copy-mode-current-match-style bg=magenta,fg=black
	copy-mode-mark-style bg=red,fg=black
	fill-character ''
	main-pane-height 24
	main-pane-width 80
	mode-keys vi
	mode-style fg=black,bg=colour39
	monitor-activity off
	monitor-bell on
	monitor-silence 0
	other-pane-height 0
	other-pane-width 0
	pane-active-border-style fg=colour39,bg=default
	pane-base-index 1
	pane-border-format "#{?pane_active,#[reverse],}#{pane_index}#[default] \"#{pane_title}\""
	pane-border-indicators colour
	pane-border-lines single
	pane-border-status off
	pane-border-style fg=colour238,bg=default
	pane-colours
	popup-style default
	popup-border-style default
	popup-border-lines single
	remain-on-exit off
	remain-on-exit-format "Pane is dead (#{?#{!=:#{pane_dead_status},},status #{pane_dead_status},}#{?#{!=:#{pane_dead_signal},},signal #{pane_dead_signal},}, #{t:pane_dead_time})"
	scroll-on-clear on
	synchronize-panes off
	window-active-style default
	window-size latest
	window-style default
	window-status-activity-style fg=colour75,bg=colour233
	window-status-bell-style reverse
	window-status-current-format " #I:#W#F "
	window-status-current-style fg=black,bg=colour39
	window-status-format " #I:#W#F "
	window-status-last-style default
	window-status-separator ''
	window-status-style default
	wrap-search on
	xterm-keys on

Step 3: Describe the problem:

Steps to reproduce:

Have a file like this:

session_name: some name
windows:
  - window_name: a
    layout: main-vertical
    options:
      main-pane-width: 50%
    shell_command_before: cd ~/work/a
    panes:
      - nvim
      - neofetch
  - window_name: b
    layout: main-vertical
    options:
      main-pane-width: 50%
    shell_command_before: cd ~/work/b
    panes:
      - nvim
      - neofetch

Do

tmuxp load ~/.config/tmuxp/some_name.yml

Observed Results:

Traceback (most recent call last):
  File "/opt/homebrew/bin/tmuxp", line 8, in <module>
    sys.exit(cli.cli())
             ^^^^^^^^^
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp/cli/__init__.py", line 134, in cli
    command_load(
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp/cli/load.py", line 642, in command_load
    load_workspace(
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp/cli/load.py", line 436, in load_workspace
    _load_attached(builder, detached)
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp/cli/load.py", line 184, in _load_attached
    builder.build()
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp/workspace/builder.py", line 292, in build
    for window, window_config in self.iter_create_windows(session, append):
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp/workspace/builder.py", line 420, in iter_create_windows
    window.set_window_option(key, val)
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/libtmux/window.py", line 346, in set_window_option
    self.refresh()
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/libtmux/window.py", line 84, in refresh
    return super()._refresh(
           ^^^^^^^^^^^^^^^^^
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/libtmux/neo.py", line 174, in _refresh
    obj = fetch_obj(
          ^^^^^^^^^^
  File "/opt/homebrew/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/libtmux/neo.py", line 242, in fetch_obj
    assert obj is not None
           ^^^^^^^^^^^^^^^
AssertionError

Sometimes when I run the command immediately again, it works, but only creates the first window of the two

Expected Results:

Create and open the new session with both windows and all panels

[tony]

@mirosval I am seeing this intermittently locally, as well. This seems like a serious issue.

Specifically - it happens on or around set_window_option.

If you have more information or find a way to reliably produce it - that would be a huge gift

[tony]

@mirosval If you or anyone else encountering this removes their options, does it change anything?

[xbatist]

I have the same issue and removing the options, I can load the configuration and have a working session (without the adjustment specify by options obviously).

[mirosval]

@tony I can confirm that commenting out options results in both windows and all commands setting up properly. Of course with the incorrect scaling now, as the main-pane-width is not applied.

[cmollet]

I am also experiencing this, but with a config that has no options block, just window_name, layout, and panes

[tony]

I am also experiencing this, but with a config that has no options block, just window_name, layout, and panes

What's the traceback look like?

[tony]

For anyone else posting, if you can provide your full config + tmuxp debug-info + the traceback that would be valuable!

[cmollet]

I am also experiencing this, but with a config that has no options block, just window_name, layout, and panes

What's the traceback look like?

WELL, I just tried it again and it worked, so I guess at best I can now say it is intermittent for me as well. However, the traceback posted by @mirosval looks very similar to what I remember, assert obj is not None was definitely the Exception.

tmuxp config

---

session_name: logs-vertical

windows:
  - window_name: host1
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host2
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host3
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host4
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host5
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host6
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host7
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host8
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host9
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host10
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host11
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED
  - window_name: host12
    layout: tiled
    panes:
      - ssh -t REDACTED
      - ssh REDACTED
      - ssh -t REDACTED

tmuxp debug-info

-------------------------
environment:
	dist: macOS-13.1-x86_64-i386-64bit
	arch: x86_64
	uname: Darwin; REDACTED; 22.2.0
	version: Darwin Kernel Version 22.2.0: Fri Nov 11 02:08:47 PST 2022; root:xnu-8792.61.2~4/RELEASE_X86_64
-------------------------
python version: 3.11.1 (main, Dec 23 2022, 09:39:26) [Clang 14.0.0 (clang-1400.0.29.202)]
system PATH: REDACTED
tmux version: 3.3
libtmux version: 0.18.2
tmuxp version: 1.24.0
tmux path: /usr/local/bin/tmux
tmuxp path: /usr/local/Cellar/tmuxp/1.24.0/libexec/lib/python3.11/site-packages/tmuxp
shell: /bin/zsh
-------------------------
tmux sessions:
	prod: 18 windows (created Thu Jan  5 09:23:19 2023)
	tasks: 3 windows (created Thu Jan  5 11:47:03 2023) (attached)
�[31m

�[39m
tmux windows:
	1: nvim (3 panes) [274x72] [layout 52eb,274x72,0,0{137x72,0,0,115,136x72,138,0[136x36,138,0,116,136x35,138,37,122]}] @44
	2: nvim- (3 panes) [274x72] [layout 78eb,274x72,0,0{137x72,0,0,118,136x72,138,0[136x36,138,0,120,136x35,138,37,121]}] @46
	3: nvim* (1 panes) [274x59] [layout b564,274x59,0,0,124] @48 (active)
�[31m

�[39m
tmux panes:
	1: [274x59] [history 10/10000, 40528 bytes] %124 (active)
�[31m

�[39m
tmux global options:
	@cpu_high_bg_color "#[bg=red]"
	@cpu_high_fg_color "#[fg=default]"
	@cpu_low_bg_color "#[bg=green]"
	@cpu_low_fg_color "#[fg=default]"
	@cpu_medium_bg_color "#[bg=yellow]"
	@cpu_medium_fg_color "#[fg=default]"
	@plugin laktak/extrakto
	activity-action other
	assume-paste-time 1
	base-index 1
	bell-action any
	default-command /bin/zsh
	default-shell /bin/zsh
	default-size 80x24
	destroy-unattached off
	detach-on-destroy on
	display-panes-active-colour colour33
	display-panes-colour colour166
	display-panes-time 1000
	display-time 2500
	history-limit 10000
	key-table root
	lock-after-time 0
	lock-command "lock -np"
	message-command-style bg=black,fg=yellow
	message-style bg=colour235,fg=colour166
	mouse off
	prefix C-a
	prefix2 None
	renumber-windows on
	repeat-time 500
	set-titles on
	set-titles-string "#S@#H"
	silence-action other
	status on
	status-bg default
	status-fg default
	status-format[0] "#[align=left range=left #{E:status-left-style}]#[push-default]#{T;=/#{status-left-length}:status-left}#[pop-default]#[norange default]#[list=on align=#{status-justify}]#[list=left-marker]<#[list=right-marker]>#[list=on]#{W:#[range=window|#{window_index} #{E:window-status-style}#{?#{&&:#{window_last_flag},#{!=:#{E:window-status-last-style},default}}, #{E:window-status-last-style},}#{?#{&&:#{window_bell_flag},#{!=:#{E:window-status-bell-style},default}}, #{E:window-status-bell-style},#{?#{&&:#{||:#{window_activity_flag},#{window_silence_flag}},#{!=:#{E:window-status-activity-style},default}}, #{E:window-status-activity-style},}}]#[push-default]#{T:window-status-format}#[pop-default]#[norange default]#{?window_end_flag,,#{window-status-separator}},#[range=window|#{window_index} list=focus #{?#{!=:#{E:window-status-current-style},default},#{E:window-status-current-style},#{E:window-status-style}}#{?#{&&:#{window_last_flag},#{!=:#{E:window-status-last-style},default}}, #{E:window-status-last-style},}#{?#{&&:#{window_bell_flag},#{!=:#{E:window-status-bell-style},default}}, #{E:window-status-bell-style},#{?#{&&:#{||:#{window_activity_flag},#{window_silence_flag}},#{!=:#{E:window-status-activity-style},default}}, #{E:window-status-activity-style},}}]#[push-default]#{T:window-status-current-format}#[pop-default]#[norange list=on default]#{?window_end_flag,,#{window-status-separator}}}#[nolist align=right range=right #{E:status-right-style}]#[push-default]#{T;=/#{status-right-length}:status-right}#[pop-default]#[norange default]"
	status-format[1] "#[align=centre]#{P:#{?pane_active,#[reverse],}#{pane_index}[#{pane_width}x#{pane_height}]#[default] }"
	status-interval 1
	status-justify left
	status-keys vi
	status-left "#[fg=green]#H #[fg=white]• #{cpu_bg_color}#{cpu_fg-color} #{cpu_icon}#{cpu_percentage} #[fg=white]• #[fg=green,bright]#[default]"
	status-left-length 50
	status-left-style default
	status-position bottom
	status-right "#{prefix_highlight} #[fg=green,bg=default,bright] #[fg=red,dim,bg=default]#[fg=white,bg=default]%a %k:%M#[default] #[fg=blue]%Y-%m-%d"
	status-right-length 140
	status-right-style default
	status-style bg=colour235,fg=colour136
	update-environment[0] DISPLAY
	update-environment[1] SSH_ASKPASS
	update-environment[2] SSH_AGENT_PID
	update-environment[3] SSH_CONNECTION
	update-environment[4] SSH_AUTH_SOCK
	update-environment[5] WINDOWID
	update-environment[6] XAUTHORITY
	update-environment[7] TERM
	visual-activity on
	visual-bell off
	visual-silence off
	word-separators "!\"#$%&'()*+,-./:;<=>?@[\\]^`{|}~"
�[31m

�[39m
tmux window options:
	cursor-colour none
	cursor-style default
	aggressive-resize on
	allow-passthrough off
	allow-rename off
	alternate-screen on
	automatic-rename on
	automatic-rename-format "#{?pane_in_mode,[tmux],#{pane_current_command}}#{?pane_dead,[dead],}"
	clock-mode-colour green
	clock-mode-style 24
	copy-mode-match-style bg=cyan,fg=black
	copy-mode-current-match-style bg=magenta,fg=black
	copy-mode-mark-style bg=red,fg=black
	fill-character ''
	main-pane-height 24
	main-pane-width 80
	mode-keys vi
	mode-style bg=brightwhite,fg=blue
	monitor-activity on
	monitor-bell on
	monitor-silence 0
	other-pane-height 0
	other-pane-width 0
	pane-active-border-style fg=colour240
	pane-base-index 1
	pane-border-format "#{?pane_active,#[reverse],}#{pane_index}#[default] \"#{pane_title}\""
	pane-border-indicators colour
	pane-border-lines single
	pane-border-status off
	pane-border-style fg=colour235
	pane-colours
	popup-style default
	popup-border-style default
	popup-border-lines single
	remain-on-exit off
	remain-on-exit-format "Pane is dead (#{?#{!=:#{pane_dead_status},},status #{pane_dead_status},}#{?#{!=:#{pane_dead_signal},},signal #{pane_dead_signal},}, #{t:pane_dead_time})"
	scroll-on-clear on
	synchronize-panes off
	window-active-style default
	window-size latest
	window-style default
	window-status-activity-style reverse
	window-status-bell-style reverse
	window-status-current-format "#I:#W#{?window_flags,#{window_flags}, }"
	window-status-current-style fg=brightblue
	window-status-format "#I:#W#{?window_flags,#{window_flags}, }"
	window-status-last-style default
	window-status-separator " "
	window-status-style fg=colour244,bg=default
	wrap-search on
	xterm-keys on
�[31m

�[39m

[tony]

Thank you!

However, the traceback posted by @mirosval looks very similar to what I remember, assert obj is not None was definitely the Exception.

if by chance it happens against and you have the full traceback, it'd be helpful to see!