They are set the same everywhere that I can think of. I deleted the file and I still get the same error. :(

What are your values for

Disk: use at most __ GB
Disk: leave free at least __ GB
Disk: use at most __% of total

?

Gruß,
Gundolf

Aha, your post at Einstein shows the problem:

No disk space available: disk_max_used_gb 0.00GB disk_max_used_pct 75.00 disk_min_free_gb 0.00GB
No disk space available: host.d_total 78.74GB host.d_free 69.86GB host.d_boinc_used_total 29.90GB
No disk space available: x1 -20.90GB x2 29.16GB x3 69.76GB x -20.90GB

and

Gamma-ray pulsar search #1 needs 19.07MB more disk space. You currently have 0.00 MB available and it needs 19.07 MB.
Binary Radio Pulsar Search (Arecibo) needs 152.59MB more disk space. You currently have 0.00 MB available and it needs 152.59 MB.

So someplace you've set "Disk: use at most 0 GB". Most probably in the local preferences. Clear them or when you don't use the GUI, exit BOINC, delete global_prefs_override.xml and restart BOINC.