Unable to extend Quality Profile in Firefox, error in console


  • SonarQube 7.9.2
  • Firefox 75.0


When attempting to extended an existing Quality Profile in the SonarQube UI using Firefox 75.0 (latest version as of this writing), either nothing will happen, or a new Quality Profile will be created for the language, instead of creating a new Quality Profile extension.

Whether it’s one outcome or the other appears to be random, although based on some brief testing I’ve done it may be centered around using a longer name and/or including spaces in the name.

In both cases, an uncaught exception: undefined error is shown in the Firefox developer console. Unfortunately this error doesn’t include any info:


This was also reproduced in a Firefox private window with no extensions loaded.

This behavior and the console error do not happen in any Chromium-based browser.


Use any Chromium-based browser to extend Quality Profiles, e.g. Chrome, Microsoft Edge, Brave.


  1. Navigate to Quality Profiles in Firefox 75.0
  2. Open the Firefox developer console (F12)
  3. Select the gear icon next to any Quality Profile and select the Extend option
  4. Enter a name for extended profile and select Copy
  5. Note the page simply refreshes or a new profile is created, instead of creating a new profile extension. In both cases, the above error is displayed in the console