(please keep CC'ing in the list address) kepes.krisztian wrote:

...

I find that hard to believe in Zope 2.7.2. Can you post an example traceback?

Sorry, I cannot do that, because the I get this problem only once, Never again. And the error_log is updated wit another traceback infos...

...then you should check the box in the error_log object that sends error log entries the the event log, so you'll have a record of it.

One thing sure: when I get these error, I see traceback infos (objects, etc) in the screen. But I don't know, that it is caused by zope system, or my error_message (what is un-renderable by a link to a session object),

Well, try your error messsage out with other errors and see what happens ;-) Chris -- Simplistix - Content Management, Zope & Python Consulting - http://www.simplistix.co.uk