The mod Task List (0.6.0) caused a non-recoverable error.
Please report this error to the mod author.

Error while running event TaskList::on_player_changed_force (ID 68)
TaskList/scripts/gui/tasks/index.lua:357: attempt to index local 'force_table' (a nil value)
stack traceback:
TaskList/scripts/gui/tasks/index.lua:357: in function 'new'
TaskList/scripts/player-data.lua:34: in function 'refresh'
TaskList/control.lua:188: in function <TaskList/control.lua:177>
stack traceback:
[C]: in function 'newindex'
__factory-planning-room/sheets/planning_mode.lua:120: in function 'enter_planning_mode'
factory-planning-room/sheets/planning_mode.lua:335: in function 'toggle_planning_mode'
factory-planning-room/scripts/events.lua:93: in function <factory-planning-room/scripts/events.lua:86>

Mod page for Task List: https://mods.factorio.com/mod/TaskList

I tried to report the issue for that mod as well, however I was not able to create a codeberg account since email verification didn't seem to work.

I've seen it and will fix it. Join the Discord server to stay up to date with the latest news and to share more detailed bug reports.

Hi! I figured out what the problem was.

The error isn't actually in my mod, but in Task List itself—you can see it right from the trace: TaskList/scripts/gui/tasks/index.lua:357. When you enter the planning room, my mod temporarily switches you to a separate service "force" to isolate the planning surface from your actual team—this is a completely standard feature in Factorio, and many mods do this. But this switch generates an event that Task List is subscribed to, and it doesn't have a check in place to ensure it doesn't know about this force yet—that's why it crashes with nil.

So, you need to fix it on Task List's side; I don't see anything broken here.