Lot of translation errors after upgrade to Matomo 5.0.1 : "The string ***_*** was not loaded in javascript"


I upgraded from Matomo 4.13 to Matomo 5.0.1.
There were no errors during file and database update, but now we have a lot of missing french translations on many pages (dashboard, settings, etc).

In english, everything is fine, all texts are displayed.

This is what I checked :

  • File integrity is OK
  • All plugins are up to date
  • Undisplayed translations are present in the langs/fr.json file of the corresponding plugin

When translations are missing, there is a JS problem on the page.
Here is the error that I got in dev tools :

Uncaught SyntaxError: Unexpected token ';' (at index.php?module=UsersManager&action=userSettings&idSite=1&period=day&date=yesterday:67:20)

And the code causing the error in index.php :

<script type="text/javascript">
var translations = ;
if (typeof(piwik_translations) == 'undefined') { var piwik_translations = new Object; }for(var i in translations) { piwik_translations[i] = translations[i];} 

This means $clientSideTranslations is empty in core/Translation/translator.php (line 205).

Do you have any idea what is causing this problem ?