Help! 500 Error when trying to create Adoptables, Items, Shops, Links?

[Storyteller]

Okay, I figured out the adoptable, shop, and item thing, at least part way. I fresh reinstalled again, and tested everything step by step until it went wrong. Everything (except adding new links) was working great, I uploaded 4 images for pet stages. I got the 500 Internal Error issue again right after I uploaded 10 tiny images to be items. So, I guess I'll just use images hosted off-site instead, and things should keep working. Still have no idea why uploading images causes that problem, and still don't know why trying to add or edit a link causes the 500 Error, but, I'm working on it! ^^

EDIT: Also, deleting those items from my File Manager doesn't fix the problem.... looks like I'm going to have to fresh reinstall again! -.-;