The mod Train Alert GUI caused a non-recoverable error.
Please report this error to the mod author.

Error while running event Train_Alerts::on_gui_closed (ID 84)
Gui element with name tral_settings-frame already present in the parent element.
stack traceback:
Train_Alerts/script/EGM_Frame.lua:5: in function 'build'
Train_Alerts/script/gui_settings_window.lua:35: in function 'build_frame'
Train_Alerts/script/gui_settings_window.lua:116: in function 'reset'
Train_Alerts/script/gui_settings_window.lua:125: in function 'get_frame'
Train_Alerts/script/gui_settings_window.lua:316: in function 'handler'
Train_Alerts/control.lua:56: in function <Train_Alerts/control.lua:54>
stack traceback:
[C]: in function 'add'
Train_Alerts/script/EGM_Frame.lua:5: in function 'build'
Train_Alerts/script/gui_settings_window.lua:35: in function 'build_frame'
Train_Alerts/script/gui_settings_window.lua:116: in function 'reset'
Train_Alerts/script/gui_settings_window.lua:125: in function 'get_frame'
Train_Alerts/script/gui_settings_window.lua:316: in function 'handler'
Train_Alerts/control.lua:56: in function <Train_Alerts/control.lua:54>

Factorio version 0.17.33
Mod version 0.4.3

Thanks for your report. This should be fixed in 0.4.4.

Nope, not fixed:

stack traceback:
Train_Alerts/script/EGM_Frame.lua:5: in function 'build'
Train_Alerts/script/gui_alert_window.lua:28: in function 'build_frame'
Train_Alerts/script/gui_alert_window.lua:110: in function 'reset'
Train_Alerts/script/gui_alert_window.lua:128: in function 'get_table'
Train_Alerts/script/gui_alert_window.lua:179: in function 'handler'
Train_Alerts/control.lua:9: in function 'raise_private_event'
Train_Alerts/script/train_state_monitor.lua:195: in function <Train_Alerts/script/train_state_monitor.lua:186>
stack traceback:
[C]: in function 'add'
Train_Alerts/script/EGM_Frame.lua:5: in function 'build'
Train_Alerts/script/gui_alert_window.lua:28: in function 'build_frame'
Train_Alerts/script/gui_alert_window.lua:110: in function 'reset'
Train_Alerts/script/gui_alert_window.lua:128: in function 'get_table'
Train_Alerts/script/gui_alert_window.lua:179: in function 'handler'
Train_Alerts/control.lua:9: in function 'raise_private_event'
Train_Alerts/script/train_state_monitor.lua:195: in function <Train_Alerts/script/train_state_monitor.lua:186>

That is a slightly different error. I assume the error message is "Gui element with name tral_alert_frame already present in the parent element.". If so, it was introduced by my fix, but I am not quite sure why. Would you be willing to share your save file (PM me on the forums if you don't want to share it publicly). I think I can fix the problem without it, but would still like to understand exactly how this happens.

Edit: 0.4.5 fixes this (again, for real this time, fingers crossed :D). Would still like to have a look at your save before that error, if you are willing to share.

I can share the save, no problem, it's not like it's top secret stuff ;) But the underlying modpack is another story...

The map: https://www.dropbox.com/s/i7hm6urkualasu5/map.zip?dl=0

Thank you. Some people are a bit touchy when it comes to sharing saves, that's why I always ask like that. Fortunately I don't need the mod pack to do my debugging.