Error 403 when saving the page

[vermeyer]

Hello,
I've recently been having a problem with a Processwire installation that's been running for over two years. The CMS is hosted by IONOS. When I try to save a new page, I get a 403 error message from the web server. Even updating to the latest version, 3.0.259, didn't solve the problem.
Can anyone help me with this issue?

[Tiberium]

@vermeyer That is because of IONOS overacting on their security for WordPress Users, see post down with a workaorund:

 

[vermeyer]

24 minutes ago, Tiberium said:

Thanks for the quick reply. Cloning the page doesn't work either - I've already tried that.
I tried the workaround in READY.PHP. It's working now.
Thanks again.