XF 1.2 500 Internal Server Error on Sign Up

Hey everyone. I have been getting a 500 Internal Server Error when myself and other users click the confirmation link in our emails to sign up and verify. I can't seem to fix this. I do not receive the error anywhere else to my knowledge.

I have looked for errors, and nothing. Any help?
Does it happen if you disable add-ons? Do you have any errors in your Server Error Logs (not in the ACP)?
I have disabled all addons and tried and still failed. I asked my host provider about the error logs but they haven't responded yet. They do not use cPanel so i have no idea where they are located. They are new to me.

Check your .htaccess file / Restore default .htaccess file, or just remove it temporarily.
I have replaced the file twice already with the upgrade package.

EDIT: I fixed the problem. The URL had a trailing "/" and was pointing to an old subdomain. Thanks anyways guys!