Down since 2024-04-30 20:00:00 UTC.
Needed 2 files for soap client:
http://schemas.xmlsoap.org/soap/encoding/
http://schemas.xmlsoap.org/soap/envelope/
and those 2 seem to be soap 1.1.
Found:
https://de.wikipedia.org/wiki/Liste_der_XML-Namensr%C3%A4ume
where you can find
https://www.w3.org/2003/05/soap-encoding
https://www.w3.org/2003/05/soap-envelope/
but in soap version 1.2.
I was lucky that i have downloaded those files (soap 1.1) some time ago when similar problems happen.
But i cannot share them because i dont know if i am allowed to (i think im not).
Perhaps the wiki page helps you.