I ran through install.php . I can now attach small files (~100k), but at 1Mb I get the following error instead ...

APPLICATION ERROR 0000401

Database query failed. Error received from database was 0002006: MySQL server has gone away for the query: INSERT INTO mantis_bug_file_table
(bug_id, title, description, diskfile, filename, folder, filesize, file_type, date_added, content, user_id)
VALUES

Note. Schema version = 173

I have updated my installation to 1.2.0cRC1 .
When I attempt to attach a jpg file (1.84 MB), Mantis crashes.

After posting this note, I will try to upload the image file to THIS installation. If it works, then maybe I need to upgrade again to the current git.

Looks like your attachment upload succeeded. Should we resolve this issue as fixed?

No, the issue is not resolved. I tested it just now.

This is reproducable. My test is this.

1. Create a new issue.
2. Select Upload File | Browse... . Note, on my system the displayed label under "Select File" is "(Max. size: 16,000k)".
3. I select a file to upload. The file has size 2,865,664 bytes . This is under the designated limit.
4. I click the "Upload File" button.
5. Mantis crashes with the following error message:
   Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 6973241 bytes) in D:\Application Services\xampp\htdocs\mantis\core\error_api.php on line 378

Note, at this time, my installed version of Mantis is:
MantisBT 1.2.0a3 2009-06-11-master-d9978e5

My guess from what you've said is that another unrelated error occurred, and Mantis' error reporting is trying to dump the entire file contents in the backtrace (thus exhausting huge amounts of memory)?

Perhaps. The problem is definitely derived from file size though. Below a certain threshold of file size (about 1MB), I consistently can attach without problem. Above the threshold, I consistently get the problem.

Because Mantis at www.mantisbt.org doesnt have the problem, but my local installation does, I suspect that does local enviromental issue is at play.

I could modify my installation of Mantis to include some appropriate diagnostic information in relation to this issue. Could you give me some hints as to how to go about this? Does Mantis have an in-built logging function that I can leverage for this purpose?

sdurkin, this issue is not reproducible with current version of MantisBT.
Feel free to reopen the issue if there are still problems after upgrading.
Maybe your problem is caused by settings of MantisBT ($g_max_file_size), PHP (upload_max_filesize) or mySQL (max_allowed_packet)