Fatal exception of type "Error" on MW1.31

[marcluer]

After installation, DrawioEditor 1.1 (d5f64f8) and NativeSvgHandler 1.3.2 (b5739af) show up fine on the "Version" page of my MediaWiki 1.31.10.
When editing an empty page, adding "{{#drawio:ChartName}}"and saving, I get the following error:

Internal error [13c6d33a32cbb7abf315266b] 2020-10-24 13:01:39: Fatal exception of type "Error"

With $wgShowExceptionDetail = true, I get:

[896dc7487e447ebbf9eccfc6] /index.php?title=Netzwerk&action=submit Error from line 91 of /var/www/extensions/DrawioEditor/src/DrawioEditor.php: Call to undefined method MediaWiki\MediaWikiServices::getRepoGroup()
Backtrace:
#0 /var/www/includes/parser/Parser.php(3426): MediaWiki\Extension\DrawioEditor\DrawioEditor->parse(Parser, string)
#1 /var/www/includes/parser/Parser.php(3127): Parser->callParserFunction(PPFrame_DOM, string, array)
#2 /var/www/includes/parser/Preprocessor_DOM.php(1277): Parser->braceSubstitution(array, PPFrame_DOM)
#3 /var/www/includes/parser/Parser.php(2942): PPFrame_DOM->expand(DOMElement, integer)
#4 /var/www/includes/parser/Parser.php(1293): Parser->replaceVariables(string)
#5 /var/www/includes/parser/Parser.php(443): Parser->internalParse(string)
#6 /var/www/includes/content/WikitextContent.php(323): Parser->parse(string, Title, ParserOptions, boolean, boolean, NULL)
#7 /var/www/includes/content/AbstractContent.php(516): WikitextContent->fillParserOutput(Title, NULL, ParserOptions, boolean, ParserOutput)
#8 /var/www/includes/page/WikiPage.php(2129): AbstractContent->getParserOutput(Title, NULL, ParserOptions)
#9 /var/www/includes/page/WikiPage.php(1655): WikiPage->prepareContentForEdit(WikitextContent, NULL, User, string, boolean)
#10 /var/www/includes/EditPage.php(2214): WikiPage->doEditContent(WikitextContent, string, integer, boolean, User, string, array, integer)
#11 /var/www/includes/EditPage.php(1506): EditPage->internalAttemptSave(array, boolean)
#12 /var/www/includes/EditPage.php(652): EditPage->attemptSave(array)
#13 /var/www/includes/actions/EditAction.php(60): EditPage->edit()
#14 /var/www/includes/actions/SubmitAction.php(38): EditAction->show()
#15 /var/www/includes/MediaWiki.php(500): SubmitAction->show()
#16 /var/www/includes/MediaWiki.php(294): MediaWiki->performAction(Article, Title)
#17 /var/www/includes/MediaWiki.php(818): MediaWiki->performRequest()
#18 /var/www/includes/MediaWiki.php(524): MediaWiki->main()
#19 /var/www/index.php(42): MediaWiki->run()
#20 {main}

What am I missing to get this working?

[marcluer]

Ok, I figured it out.

1. Make sure to use the REL1_31 extension code for MediaWiki 1.31.x
2. Use require_once "$IP/extensions/DrawioEditor/DrawioEditor.php";, despite https://www.mediawiki.org/wiki/Extension:DrawioEditor telling you to use wfLoadExtension( 'DrawioEditor' );