=== Error ===
`MediaWiki version:` **`1.35.0-wmf.14`**
```name=message
Fatal TypeError:
Return value of ResourceLoaderImage::getLangFallbacks() must be of the type array, null returned
```
```name=exception.trace,lines=10
#0 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImage.php(174): ResourceLoaderImage->getLangFallbacks(string)
#1 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImageModule.php(452): ResourceLoaderImage->getPath(ResourceLoaderContext)
#2 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImageModule.php(438): ResourceLoaderImageModule->getFileHashes(ResourceLoaderContext)
#3 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderModule.php(819): ResourceLoaderImageModule->getDefinitionSummary(ResourceLoaderContext)
#4 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderStartUpModule.php(300): ResourceLoaderModule->getVersionHash(ResourceLoaderContext)
#5 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderStartUpModule.php(484): ResourceLoaderStartUpModule->getModuleRegistrations(ResourceLoaderContext)
#6 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderModule.php(713): ResourceLoaderStartUpModule->getScript(ResourceLoaderContext)
#7 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderModule.php(681): ResourceLoaderModule->buildContent(ResourceLoaderContext)
#8 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderModule.php(816): ResourceLoaderModule->getModuleContent(ResourceLoaderContext)
#9 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoader.php(667): ResourceLoaderModule->getVersionHash(ResourceLoaderContext)
#10 [internal function]: ResourceLoader->{closure}(string)
#11 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoader.php(679): array_map(Closure, array)
#12 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoader.php(766): ResourceLoader->getCombinedVersion(ResourceLoaderContext, array)
#13 /srv/mediawiki/php-1.35.0-wmf.14/load.php(43): ResourceLoader->respond(ResourceLoaderContext)
#14 /srv/mediawiki/w/load.php(3): require(string)
#15 {main}
```
=== Impact ===
The RL startup module is unable to produce a response for mrj.wikipedia.org, and for uselang=mrj on other wikis. This means mrj.wikipedia.org and mrj-language users on other wikis are consistently receiving the Grade C (no-javascript) experience on desktop and on mobile. E.g. no search suggestions, VisualEditor or WikiEditor.
=== Notes ===
The `LanguageFallback:getAll` method in MediaWiki core is consistently returning `null` instead of `array` for the `mrj` language code. Requests that have been aborted by this fatal error, also logged the following warning slightly before the fatal:
```
PHP Warning: Invalid argument supplied for foreach()
#0 /srv/mediawiki/php-1.35.0-wmf.14/includes/language/LanguageFallback.php(102): MWExceptionHandler::handleError(integer, string, string, integer, array)
#1 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImage.php(154): MediaWiki\Languages\LanguageFallback->getAll(string, integer)
#2 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImage.php(174): ResourceLoaderImage->getLangFallbacks(string)
#3 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImageModule.php(452): ResourceLoaderImage->getPath(ResourceLoaderContext)
#4 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderImageModule.php(438): ResourceLoaderImageModule->getFileHashes(ResourceLoaderContext)
#5 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderModule.php(819): ResourceLoaderImageModule->getDefinitionSummary(ResourceLoaderContext)
#6 /srv/mediawiki/php-1.35.0-wmf.14/includes/resourceloader/ResourceLoaderStartUpModule.php(300): ResourceLoaderModule->getVersionHash(ResourceLoaderContext)
```