"The upload path does not appear to be valid" (PULLING MY HAIR OUT !!!!) [SOLVED]

[eluser]Christoph Rumpel[/eluser]
I tried $config['upload_path'] = './gallery/'; too. (gallery is my folder on MAMP/htdocs/ where alle my ci files are inside.
I do not understand how path works in CI.

I have a resize function with:

$config['source_image'] = 'mypic.png';

and this is working. (http://localhost:8888/gallery/mypic.png)
This would mean the root is inside ...gallery/

Still dont get why it does not work with the upload_path without "$this->upload->initialize($config);"

Thx for the help