m.hamburg,

I was not able to reproduce your problem with a fresh install of the latest stable MantisBT release.
I recommend that you upgrade to the latest (download from [1]). If after doing so the problem persists, do not hesitate to reopen the issue and provide detailed step-by-step instructions to reproduce the issue; the following additional information may also be useful:

• Exact version of PHP, Database, Web server, Browser and Operating System
• Relevant customizations (e.g. changes in config_inc.php, etc)
• Installed plugins or custom functions ?
• Was the MantisBT source code modified in any way ?

[1] https://mantisbt.org/download.php

This is not a bug or feature request for MantisBT (you are asking for help on how to fix a random issue). I am therefore resolving this issue as "no change required".

Please use the forums to get support on customizing and using MantisBT (refer to https://mantisbt.org/support.php for links and further details).

We have been using MantisBT for several years now without experiencing such issues as recently. So, I don't think customization is a likely cause. But we will update to 2.27.0 as you requested and will see what happens.

@m.hamburg, atrol's recommendation is just best practice.

When a problem is not reproducible on our end, customization is often the cause. The issue could also be due to server/network environment. You should try to find out if something changed in your system since the problem started occurring.

In any case, we do not have sufficient information to investigate further.

We updated our installation to the latest versions, and the failure is still there.

Do you need any additional information?

Do you have any 3rd party plugins installed?
If yes, try uninstalling / deactivating them.

Search your webserver, PHP and database logs for errors and warnings.

Thanks for the swift response. Not that I know of 3rd party plugins, but I will check with our admin and ask for db logs.

I'm sorry, but the video just demonstrates the behavior without providing any helpful information that could help us understand what is going on.

As mentioned before, this problem is not reproducible by us. As far as I know, view_all_bug_page.php code does not perform any redirection to my_view_page.php. Furthermore, your statement

The failure does not always occur, but when it does, this failure systematically occurs for a period of one hour at least.

leads me to believe that it is environment-specific.

If you're using any plugins or custom code, try disabling those to see if the problem persists.

You should also analyse the requests submitted by your browser, and cross-check them with those processed by the web server, to try and figure out exactly what is triggering the redirect.

If you're sure that MantisBT code is doing this (which I doubt, as if it were the case the problem would be persistent), then you could add debugging log statements in view_all_bug_page.php / view_all_inc.php to pinpoint where it occurs.

Cross-posting, sorry

Not that I know of 3rd party plugins

Your screenshot shows "Import CSV file". This is not part of MantisBT.
There might be more, use the "Plugins" tab to check it.

We deinstallde the 3rd party plugins:

Screenshot 2025-08-18 182739.png (301,935 bytes)   

Screenshot 2025-08-18 182739.png (301,935 bytes)   

Several people in my team still experience the issue sporadically. Our admin could check the logs.
Checking the logs at the times we experience the behaviour we find issues in the session_api.php, row 249 which seems to be consistent. Can you please check this and let us know how we should proceed

Aug 8th:
[Fri Aug 08 17:38:45.044735 2025] [php:warn] [pid 1684] [client 172.71.160.29:33982] PHP Warning: 2702 in /var/www/html/mantisistqb/core/session_api.php on line 249, referer: https://mantis.istqb.org/view_all_bug_page.php
[Fri Aug 08 17:48:16.256549 2025] [php:warn] [pid 1698] [client 172.71.160.39:38374] PHP Warning: 2702 in /var/www/html/mantisistqb/core/session_api.php on line 249, referer: https://mantis.istqb.org/view_all_bug_page.php
[Fri Aug 08 19:00:23.174708 2025] [php:warn] [pid 1694] [client 172.69.109.58:14108] PHP Warning: 2702 in /var/www/html/mantisistqb/core/session_api.php on line 249, referer: https://mantis.istqb.org/my_view_page.php

Aug 18th:

[Mon Aug 18 12:19:16.701702 2025] [php:warn] [pid 75371] [client 172.69.214.180:50408] PHP Warning: 2702 in /var/www/html/mantisistqb/core/session_api.php on line 249, referer: https://mantis.istqb.org/view_all_bug_page.php
[Mon Aug 18 12:43:33.916886 2025] [php:warn] [pid 79466] [client 172.69.109.213:43330] PHP Warning: 2702 in /var/www/html/mantisistqb/core/session_api.php on line 249, referer: https://mantis.istqb.org/my_view_page.php
[Mon Aug 18 12:54:06.982086 2025] [php:warn] [pid 79628] [client 172.71.160.38:10372] PHP Warning: 2702 in /var/www/html/mantisistqb/core/session_api.php on line 249, referer: https://mantis.istqb.org/view.php?id=7322

Thanks for this. Now I understand what is happening.

Error 2702 is triggered when the user's session is not valid. In that case, Mantis redirects to the configured default home page (default of My View in your case).

A session is considered invalid when

• $g_session_validation = ON (which is the case by default),
• the user logged in with a "secure session" (i.e. Only allow your session to be used from this IP address. is checked on login page) and
• the last IP address recorded in the session is different from the user's current IP.

Note that Mantis is using REMOTE_ADDR to get the user's IP, and this can sometimes be incorrect e.g. if you're using a reverse proxy. We have no control over this.

So what we see is normal behavior from Mantis.

Now the question is, why does the IP address change ? This is a problem with your environment, not a bug with MantisBT, so I'm closing this as no change required.