**List of steps to reproduce** (step by step, including full links if applicable):
1) Log in
2) In Special:Preferences disable the compact languages link feature like so:
{F34560164}
3) Visit https://de.wikipedia.org/wiki/Berlin
4) Click the language button
{F34560172}
**What happens?**:
Most of the time the language dropdown shows like so:
{F34560174}
However, occasionally no menu will show like so:
{F34560176}
I was able to replicate this 1 / 10 times.
**Software version (if not a Wikimedia wiki), browser information, screenshots, other information, etc**:
Issue occurred on German Wikipedia.
The following gadgets are enabled:
{F34560166}
{F34560168}
{F34560170}
The **Content Translation **beta feature is enabled.
I was unable to replicate on https://de.wikipedia.org/wiki/Berlin?safemode=1
# Developer notes
It's possible the class `vector-menu--hide-dropdown` is related.
Inspecting the code this class is removed if the module `ext.uls.interface` is being loaded. Presumably a race condition exists where some code loads that module.
https://gerrit.wikimedia.org/g/mediawiki/skins/Vector/+/b621b3836f9d2396e379e11cd1d788984c7f3d00/resources/skins.vector.js/languageButton.js#6
# QA steps
# Scenario 1
- Visit https://en.wikipedia.beta.wmflabs.org/wiki/Selenium_language_test_page incognito window
- Click the language button
- Expected: the dialog shows with "search for language"
# Scenario 2
- Login
- Visit https://en.wikipedia.beta.wmflabs.org/wiki/Special:Preferences and disable the box "Use a compact language list, with languages relevant to you." at bottom of appearance section
- Visit https://en.wikipedia.beta.wmflabs.org/wiki/Selenium_language_test_page
- Click the language button
- Expected: a scrollable list should appear.