Misbehaving 'Close' button in html view popup

Misbehaving 'Close' button in html view popup

I use custom 'View' buttons to open records in my views (with ... href=\ \"#View:myView?zc_LoadIn=dialog&recID=... in a Formula Field). This has been working nicely for a long time.

Since fairly recently, the 'Close' button/link is suddenly outside the popup (in the "dark" area surrounding the popup) and is displayed in plain black text. I really have to search for it... 

Any help appreciated.


Regards, Filip

PS to Zoho Team: App in question: bmpm; Edit access is granted.