Installing new modules to joomla after it's uploaded

I can’t install a module and it tells me:
" * JFolder::create: Path not in open_basedir paths
* Warning! Failed to move file.
I have put in joomla global setting that the temp dir is “/tmp” and then “”, but it didn’t work in any case.

What should I do?

Are other extensions (mambots, modules, components, templates, …) working?

I found out what the problem was! I went to “Help>System Info>PHP Settings” and copied the Session Save Path: /users/oldradiorepairs/temp (where oldradiorepairs is my username in bplaced) in Global Configuration>Server> Path to Temp-folder.
Now, I can install anything online!