My permissions are correct, world-readable. I cannot import token csv. Tried export then re-import survey file. Same error. Seems a server issue, but checked from several directions and permissions are 777 for limesurvey/tmp and limesurvey/upload.

What can I do?

Version 1.90+ Build 9642
PHP 5

1. What is the exact error message?

2. Is there any temporary file created at /limesurvey/tmp?

1) "Upload file not found. Check your permissions and path for the upload directory"

2) No.

2a) /tmp /upload directories ARE fully world-readable.

3. Can you copy a template at the template editor without errors?

4. Which URL do you use to log in at the admin backend and what did you set as $rooturl in config.php?

3) Yes, I can copy a template, BUT, I cannot upload files into the template without:
Error
An error occurred uploading your file. This may be caused by incorrect permissions in your /usr/home/schcor/www/htdocs/limesurvey/tmp folder.
(tmp is set at 777)

4) Address: www.schc.org/limesurvey/admin/admin.php
$rooturl = "http://{$_SERVER}/limesurvey"

The path configuration looks fine.

It's pretty sure still a permission problem, /tmp has to be writeable AND scripts should be allowed to create files there.
Maybe your provider can fix it.