Why visual editing is gone?

Question

Overnight the visual editing is gone from our JIRA. All markup is shown and no more "Text" and "Visual" tabs are shown below the edit box.

I do not see anything special in the logs...

Rich Text Editing option is turned on. I tried turning it off and on - no change.  Restarted JIRA - no change.

What could be the issue? What else can I do?

Przemek Czernek · Accepted Answer

I still do not know why this happened, but fixed as described in https://community.atlassian.com/t5/Jira-Software-questions/Rich-text-editor-enabling/qaq-p/1015017