Can you check the browser javascript console when the problem occured to see if there’s any error? Can you also check the browser network tab, you should see a request to a path containing /save/ probably with some 500 status: it would help to have the actual content of this answer.
Finally you could check the xwiki server logs when it happens it might display the root cause of the error.
I created a new ‘Simple Page’ .
On the 1st save I had the error (as above). In the Firefox Web Developer console
Warning: The script from “https://…/bin/get/CKEditor/Config?outputSyntax=plain&t=K9DA” was loaded even though its MIME type (“text/plain”) is not a valid JavaScript MIME type. WebHome
Error: Blocked loading mixed active content “http://…/rest/jobstatus/refactoring/create/1605709180678-429?media=json” prototype.js:1745:21
And the Network Tab shows an error xhr ‘Mixed Block’ on the last line. There is no /save/ in the Network Tab
When I click a 2nd time the document is saved and the above errors do not appear.
There is nothing obvious in the /usr/local/tomcat/logs
I cleared the cache and restarted Firefox.
With the Network Tab open I create a new Simple Page. On Save&Continue the error message Failed to save the page. Reason: Server not responding appears and one line is added to the Network Tab showing the error error xhr ‘Mixed Block’ .
Similarly on the chrome browser and I get the same result. The Network Tab shows
Status = blocked:mixed-content
Type = xhr
Initiator = prototype.js:1745
Not 100% sure any more, but I believe to remember to experience a similar issue when using a macro to trigger the page creation from a template. I have set
xwiki.cfg:xwiki.url.protocol=https
in my config, which might have mitigated this (or I changed the way the template was used … )
Only to make sure: you restarted your Java container, right?
The request is status 200, but as @surli mentioned, your browser will potentially block this. So my memory failed me and I did something else to circumvent this… but I don’t remember what … I’ll try to find it…
I have same situation, on initial save I get same error. When checking browser I see that browser tries to connect xwiki private ip and not domain name?