Created attachment 123637 [details]
version=3 profile created with 4.2.3

SUMMARY

There is a regression in the settings handling between relatively minor dot releases, from 4.2.3 -> 4.2.7.1b

When going from 4.2.3 -> 4.2.7.1b (and 4.2.7.1), my desired input profile wasn't read, leading me to not be able to interact with Krita in my usual way, making the program feel broken.

STEPS TO REPRODUCE
0. Use 4.2.3 or possible other versions of Krita
1. Create an Input Profile in the Canvas Input Settings pane in the Configure Krita settings box
2. Set some input options, like adding new mappings for pan, rotate, and zoom canvas 
3. Click "OK" and quit Krita
4. Observe that the input profile is created in ~/.local/share/krita/input (or similar), and it's created with Version=3
5. Open 4.2.7.1b or possibly other versions of Krita, and open the same Canvas Input Settings pane

OBSERVED RESULT
The profile you created in step 1 and which is saved in ~/.local/share/krita/input doesn't show up in the input settings drop-down. Opening 4.2.3 will show your input profile still.

Note too that no error dialogs are shown about this failure, and it's actually quite hard to find without some digging and learning how things are stored in the profile

EXPECTED RESULT
The input profiles appear in the dialog box, either via migration or backwards compatibility.


SOFTWARE/OS VERSIONS
Windows: ?
macOS: ?
Linux/KDE Plasma: Debian Testing (devuan) as well as Ubuntu Disco
(available in About System)
KDE Plasma Version: I can't find the "about system" button
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
I've included one of the version 3 input profiles that wasn't upgraded automatically

I changed version=3 to version=4 and it seems to work, but this workaround may be unstable and is obviously not intended.