I'm having this exact same problem. Everything worked fine, then the attachments didn't show up and then the avatars shortly after. I'm guessing the avatars were maybe cached which is why they showed up for longer but right now all i have is broken image files.

The only thing i changed recently was the auto-increment but i don't see how that could affect it. I've run various maintenance tools in the admin cp but with no luck.

Any suggestions? And please keep in mind i am inexperienced so if there is something that needs to be done, i may need to be pointed to where it is.

You changed the auto_increment of what?

What version vb are you running? And what version of PHP and MySQL are on your server?

I was previously having this issue:
https://vborg.vbsupport.ru/showthread.php?t=313876

I'm running vb4. I believe i am using version 5.5 of php and MySQL (i'm using a2hosting).

Everything had been working originally, but now its not.

If you are running PHP5.5, then the only version of vB4.x that you may run that is compatible with that version of PHP is 4.2.3 beta. So, you need to upgrade to that.

I had a closer look as i didn't realize you were looking for the exact version.

From the vb control panel:

PHP 5.4.8
MySQL Version 5.5.34-cll-lve

vBulletin 4.2.2 Patch Level 1

It also says "Latest version available: 4.2.2 Patch Level 1"

I thought it was php/mysql 5.5 because when i went to the hosting home page thats what it mentioned but the above info is from my cp.

Have you already added this line to your config.php file? If not, please add the following line to your config.php file under the <?php line:

Have you tried Maintenance > General Update Tools > Rebuild Custom Avatars?

Are avatars stored in the database or filesystem? Have you tried changing that and then seeing if it fixes the issue?

The rebuild custom avatars helped with that issue.

I looked at the config file but could not find the php line. I'm just heading out now but will comb through it closer when i return.

Still having the issue....afraid to make any changes for fear of screwing something up

--------------- Added [DATE]1411081209[/DATE] at [TIME]1411081209[/TIME] ---------------

I took a chance and changed from database to file system....problem solved!