"Please help" internal server error when upload images

oh my goodness, I am having the exact same problem, but with MT 4.3

I am with Network Solutions, who so far have been NO help at all.

Have you had any luck with it since you posted this?

If I find out anything further I'll let you know too.

I've never heard anything good about Network Solutions as a host. I recommend Hosting Matters. Their plans aren't the cheapest shared hosting plans ($11 for 700MB of storage, 40GB of bandwidth and 7 or 8 MySQL databases), but I've found their reliability and ability to host products like Movable Type and WordPress to be impeccable.

My client's hosting needs renewing in February, so I am certainly up for suggesting a move to a new host, as I've heard other people say similar things about Network Solutions. Thanks for the suggestion.

Have you tried checking your Activity Logs (you might need to set your Debug level to 1 to get something in the logs) to see if there's anything useful there? That can be helpful sometimes if you don't have access to your server's error log (or if, like me, you're stuck on an IIS server, which has lousy error logging). I don't know about MT 5, but I was getting server errors in 4.33 due to ImageMagick not being correctly installed on my server--and I was getting those was when I was only trying to post comments. For some reason and in certain situations (I'd call it a bug, even), MT throws a fatal error instead of a warning when ImageMagick isn't installed, even though the docs say ImageMagick is optional and really only required for creating thumbnails. Since you're trying to upload images, ImageMagick could even be relevant. You can find out by checking System > Tools > System Information (or running mt-check.cgi).

HTH,
Bill