Loading window when updating case


We recently upgraded to to version 7.4.3 and everything seems to be working fine. We had an issue where we were getting a lot of undefined error messages but that turned out to be the system not being able to read the language file.

On cases now every time I save an update it comes up with “Performing task, one moment please…” and this does not close or the page refresh. If I manually refresh the page I can see that the update has been saved and shows up on case updates threaded. I have made sure that all of the permissions are correct, based on other topics on this forum however nothing has worked.

When I inspect the element I am present with the following error messages:

Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check http://xhr.spec.whatwg.org/.
Refused to set unsafe header "Content-length"caseUpdates @ index.php?module=Cases&action=DetailView&record=ef6c1d7e-5d2a-0537-6aab-56938b2cd2b9:1451
Refused to set unsafe header "Connection"caseUpdates @ index.php?module=Cases&action=DetailView&record=ef6c1d7e-5d2a-0537-6aab-56938b2cd2b9:1452
Uncaught TypeError: Cannot read property 'matches' of undefined

Any advise is appreciated.

Kind regards.