Roundcube is working great for my users, with one main complaint: Seemingly randomly, when users are attempting to send messages, it will fail with the message:
An internal error occured. Please try again.
Trying again does not fix the error, which frustrates the user. They have to abandon their message. They can continue to read mail, but any attempt at sending a message, as soon as they click Send, they get the same error again.
The only way to recover is for them to log off and re-login. They do not like this!
Looking at my error logs, I see this when this error occurs:
[Feb/25/2013 12:59:30 -0500]: PHP Error: Invalid compose ID in D:\Inetpub\wwwroot\RoundCube\program\steps\mail\sendmail.inc on line 39 (POST /?_unlock=loading1361815170438&_lang=en?_task=mail&_action=send)
What is causing the compose id to become invalid? They are not writing long messages, they could log in, click Compose, write a one-line message, click Send, and get the error, so the session (or anything else) is definitely not timing out.