I get the same thing, so it is a sham that no one has replied to you in the last 4 years.

I think that it may be due to having a blank line at the top of many of my php files, but I am not sure.

why would that be a shame ? it's not a bug or anything after all..some topics just goes lost of many reasons.. a *bump* would certainly help if you couldnt get an answer after 8 hours or so.

Many things should happen for a topic to be solved

Proper question & explanation
Mods/users around
Draw attention - of a mod/user-
Is -that- mod/user capable of answering
etc.. etc.. lack of one of these may well cause the topic to end up dead

back to the issue:

most possible reason is misconfig.Change your instance_name under conf/advanced and make sure your baseurl and cookiepath is correct too