Steps to reproduce:
- Open ULS.
- Click on Input.
- Select ... button to add new language.
- Select Punjabi (or any other language)
- Language should be added in one of the 3 buttons, but it is not.
- OS: Linux (Debian Unstable)
- Browser: Iceweasel 21.0
- Mediawiki: WMF Betalabs
This looks browser specific bug to me. Please merge if this is duplicate/resolved already.