Application_Error:In use notification already exists.

Hi,

We have issues saving content in our production environment on DXC.
We also see following error being logged in application insights:

Application_Error:In use notification already exists.

There's no more information logged except that the source is "EPiServerApplication"

All I can find was this unresolved issue of a few years ago:

https://world.episerver.com/forum/developer-forum/Developer-to-developer/Thread-Container/2016/11/ui-problems-with-publish/

What could be the issue here?

Best regards,

Brecht