Can't open page editor (AGAIN!!)

Can't open page editor (AGAIN!!)

I have an html page, and when I try to open the editor, the page hangs and never loads. The html pages still load, but I can't make changes to them. 

Anybody have any ideas? I have submitted to support already...

Last time this happened, it was because I used "count" as a variable, which is apparently not supported. I got the ever-helpful troubleshooting error of "null". 

I have not made any changes since last time this happened.

See that conversation here: https://help.zoho.com/portal/en/community/topic/can-t-open-page-editor#2266000005930001