Ubuntu version UI not loading (Insomnia unusable) starting from 12.0.0 after upgrade

[enerit-developer-team]

Expected Behavior

UI elements load, app can be used as intended, see the following screenshot from version 11.6.1

Actual Behavior

UI elements do not load, probably a bug in the HTML code. See the following screenshot from 12.4.0:

Reproduction Steps

1. Install insomnia 11.6.1 debian
2. Update to any version between 12.0.0 and 12.4.0 (inclusive) Eg. Insomnia.Core-12.4.0.deb
3. Open Insomnia

Is there an existing issue for this?

• I have searched the issue tracker for this problem.

Which sync method do you use?

• Git sync.
• Insomnia Cloud sync.
• Local only

Additional Information

No response

Insomnia Version

12.4.1

What operating system are you using?

Ubuntu

Operating System Version

25.10

Installation method

Downloaded debian package from GitHub

Last Known Working Insomnia version

11.6.1

[enerit-developer-team]

It seems that removing ~/.config/Insomnia has fixed the issue

Logs from failed startup:

[Git Providers] Initializing Git remote providers...
[Git Providers] Initialized 3 providers: github, gitlab, custom
12:39:36.821 › Running version 12.4.0
12:39:36.833 › [electron client protocol] FAILED to set default protocol 'insomnia://'
12:39:36.844 › [electron client protocol] the current executable is not the default protocol for 'insomnia://'
12:39:36.941 › [electron client protocol] the default application set for 'insomnia://' is 'insomnia.desktop
'
12:39:37.088 › [fix] Running database repairs
12:39:37.239 › [main] Checking for newer version than 12.4.0
12:39:37.240 › [updater] Using url https://updates.insomnia.rest/builds/check/mac?v=12.4.0&app=com.insomnia.app&channel=stable
12:39:37.720 › [main] Found newer version
12:39:37.731 › [main] Backup found at: /home/<username>/.config/Insomnia/backups/12.4.0
12:39:37.732 › [ElectronStorage] Initialized at /home/<username>/.config/Insomnia/localStorage
12:39:37.734 › [git-credentials-migration] Already migrated credentials, skipping migration
12:39:37.775 › [app] Failed to get instance lock