I updated from MediaWiki 1.31 to 1.34 and thus from Contributors "2.0 (bf42ccf) 03:30, 22. Nov. 2017" to "2.0 (04de8a2) 08:36, 10. Sep. 2019".
After running
```
php extensions/Contributors/maintenance/PopulateContributorsTable.php
```
the special page "Special:Contributors" works as expected.
But the inclusion with `{{Special:Contributors/Article}}` generates no output at all. It only shows 2 warnings:
```
Warning: array_keys() expects parameter 1 to be array, null given in
/html/site/mediawiki/extensions/Contributors/includes/Contributors.php on line 187
Warning: Invalid argument supplied for foreach() in
/html/site/mediawiki/extensions/Contributors/includes/Contributors.php on line 196
````
Changing to the master version of the extension doesn't fix the error.
Who can fix this please?