Cannot load vis-network.js in MediaWiki 1.39

[cicalese]

I encountered an issue where the extension will not load in my environment using MW 1.39. It is failing in load.php to retrieve vis-network.js with a 503 error. I tried updating to a newer version of vis-network.js and also tried the minified version, with no difference. Has anybody else encountered this issue?

[krabina]

No, in my testwiki it is working:
https://test.knowledge.wiki/Spezial:Network
(try entering "Adolf Loos" as page)