Cura: Custom Extruder Configuration Error

[yeowjoon99]

Application version
4.2.1

Platform
Windows 10 1903

Printer
Untitled 3mf.zip

Reproduction steps
Just open Cura

Actual results
This happens

I should probably also mention that because of this error, if I change the printer to have 7 or 8 extruders, it'll omit the 7th extruder from the UI no matter where I check. There won't be a 7th but there'll be the 8th extruder

Expected results
There shouldn't be any error at all and the 7th extruder should show up in the UI

Additional information
I've already tried to backup everything, reset and restore but the issue always come back with restoring so the problem probably lies in one of the config files.
But because I have a lot of custom materials saved I can't just reset and save it like that.
If there's any way to fix this please advise thanks

[rburema]

I could not get this to reproduce with just the printer definition (or when I adjusted the extruders to number 8 and back to 1 a few times). I think we'll need the other config files as well if we want to find out what's wrong here.

[yeowjoon99]

Which files do you think are likely culprits specifically

I think it'd be better for everyone if I didn't upload the entire folder 😅

[rburema]

The 'definition_changes', 'definitions', 'extruders' and 'machine_instances' folders, I think. (Maybe 'quality' and 'quality_changes' as well.)

[yeowjoon99]

Alright here's everything I could find.
Couldn't find 'definition_changes', 'machine_instances' and 'quality_changes' folders
I did find a .py file named 'MachineInstance.py' though

Compiled Folder&Files.zip

[rburema]

These are the ones from the installation, we have those already ;-)
There's the ones in the %appdata%/cura/<version> folder as well, which are the ones we need.

[yeowjoon99]

Ohhh I didn't realise there was a folder in %appdata% too
My bad here you go 👍
Compiled Folders.zip

[yeowjoon99]

I just did some exploring and found the cura>4.2>extruders custom_extruder_7+...... was a completely empty config

[yeowjoon99]

So being the simple person I am I just went and deleted that blank file for all my versions of cura in %appdata%/Roaming (just to be sure)

And then I restarted Cura and voila :D

Thanks a lot @rburema for the help

So to anyone in future who gets a similar problem maybe with another extruder idk, just go to %AppData%/Roaming/cura//extruders then delete the problematic config file and restart Cura 👍

[Ghostkeeper]

Most likely Cura crashed with a segfault unexpectedly or the computer closed down completely. Cura should be robust against that though... We do employ the technique of "write a temp file first, then move it in the correct location".