missing temporary folder

I’m experiencing a “missing temporary folder” issue when attempting to upload images. I’ve read all the suggestions for solving this problem, tried several, and none of them help. I cannot edit the php.ini file, but I’ve tried making changes to the Miscellaneous Settings and adding an uploads folder on the server. None of these things help. I’m hoping someone has found a solution to this issue since the last time it was raised in the forums.