Dir open: Could not open directory 'slots/0' from '/var/lib/boinc-client'
From BOINC Wiki
Simply said, you have a permission problem when you get an error like this.
To fix this, you can either:
- reinstall BOINC;
- check that you're using the correct user to run BOINC.
- slow down BOINC start at OS start-up, to allow all drivers to load first, see man sleep.