I am new to Roundcube. When I compose HTML email, the TinyMCE popup windows are blank, and I got TinyMCEPopup is undefined error. I added tinymce into plugins list in main.inc.php and it didn't help. What did I missed? Do I need to download and install TinyMCE package somewhere?
Finally figured it out, it is the local antivirus program caused the popup window blank. After turned the antivirus program, it worked fine.:)