On MediaWiki 1.43 BootstrapComponents crashes the site with this error:
TypeError: MediaWiki\Parser\ParserOutput::addModuleStyles(): Argument #1 ($modules) must be of type array, string given, called in BootstrapComponents/src/HooksHandler.php on line 232
Just adding the [ ] there removes the error.
Maybe related to: ProfessionalWiki/Bootstrap#62 ?