EDIT: The ways of the clockworks are truly mysterious, it seems that randomly trying apparently solved the issue.

I tried to log in after the latest update and the game expectedly closed and tried to update itself but something went wrong making the update screen stop (due to some mistake but I didn't pay too much attention to it sorry) so I closed it manually in hopes that relaunching the game would fix the issue.
And well now it doesn't even go past the validation step, giving out the error "Verifying resources took too long.".
Looking at the log file "launcher.log", I saw the following lines:

2026/03/27 22:58:33:419 INFO Resource failed digest check [rsrc=code/projectx-pcode.jar, error=java.nio.file.NoSuchFileException: C:\Users\ASUS\AppData\Local\Spiral Knights\app\code\projectx-pcode.jar]
2026/03/27 22:58:33:419 INFO Resource failed digest check [rsrc=code/projectx-config.jar, error=java.nio.file.NoSuchFileException: C:\Users\ASUS\AppData\Local\Spiral Knights\app\code\projectx-config.jar]
2026/03/27 22:58:33:419 INFO Resource failed digest check [rsrc=code/config.jar, error=java.nio.file.NoSuchFileException: C:\Users\ASUS\AppData\Local\Spiral Knights\app\code\config.jar]

Resulting in:
2026/03/27 22:59:36:315 WARNING getdown() failed.
java.lang.IllegalStateException: m.verify_timeout
at com.threerings.getdown.data.Application.verifyResources(Unknown Source)
at com.threerings.getdown.launcher.Getdown.getdown(Unknown Source)
at com.threerings.getdown.launcher.Getdown.run(Unknown Source)
at com.threerings.getdown.launcher.a.run(Unknown Source)

And indeed after checking the folder mentioned in the 3 aforementioned lines, those 3 files are indeed missing for some reason.
I suspect me closing the updater may have messed the files somehow. Is this the part where I have to uninstall and reinstall everything ?