I handled this and manually upgraded “XWiki Standard Flavor for sub-wikis” from 14.6 to 15.10 on the sub-wiki.
The wiki is now working as expected.
But, I guess an upgrade wizard should have been triggered at some point (cc @tmortagne)?
I’m having a similar issue: my WYSIWYG editor isn’t working anymore. It gets stuck in an infinite loop when I try to edit a page, and I no longer see the “Save,” “Save and Exit,” or “Cancel” buttons when I try to create a new page.
I have administrator privileges and am an advanced user. This has been happening since I installed the offline version of xwiki-platform-distribution-flavor-jetty-hsqldb-17.10.6. If I switch to the text editor, everything works fine, but as soon as I switch back to the WYSIWYG editor, it stops working. Do you have any idea what might be causing this problem? Because I’m on Linux, and I have an instance on Windows that works very well. But the one on Linux doesn’t work, and no matter how many times I try to reinstall from scratch, the problem persists—even after clearing the browser cache. Is there a way to figure out where this problem is coming from?