What do you mean with "crashes"?
Do you get any error message?
Did you have a look at the log-files of Apache?

What do you mean with "this issue still doesnt't seems to be solved"
Is there another issue which is related to this one?

we've updated to Manits 1.2.0 and then 1.2.1 and since this there are sometimes problems with the login.
Sometimes the people must switch the user account, so they log off and whant to login with an other account but the login hangs.
The only solution is to choose another browser or use the private mode of the browser.

What might be the prob? Session Cookie? Is there a solution out there?

Is there a debug flag to see more informations when the problem occures?
it is in house at our company so we can enable all traces which are possible...
today whe have two new users which have the problem. using the private mode of firefox solves the problem. thx

Okay, today we had the same problem with an user how had it on yesterday. problem is: he wants to login, but the browser hangs after pressing the login button with no return. after this we must close the browser to try again or use another user account to test. we'he tried the reset the passwort but if we login by "lost passwd link" and set a new one the page with the "preferences" never finishes the submit action. so we copied the passhash in mysql from another user and then: it works... but we have to restart the apache to change the copied passwdhash by the userprefs page... strange... any ideas? this occures since upgrading to mantis 1.2.0 ...

No error message is displayed.
You only get no response anymore from mantis.
Only a restart of apache solves the problem.

Following issues are related to this one:
http://www.mantisbt.org/bugs/view.php?id=11154
http://www.mantisbt.org/bugs/view.php?id=11535

Probably a duplicate of 0011535 where the problem is a buggy PHP 5.3.1 release (ie. not MantisBT's problem).

fix with tip 0011535 commenting line 349 works thx