I recently installed BOINC on one of my Ubuntu machines but it wouldn’t do any work for the World Community Grid (WCG). The message log showed ‘Scheduler request failed: peer certificate cannot be authenticated with known CA certificates’. I tracked the problem down on the BOINC website. It is caused by a missing digital certificate that is required by WCG but not included with Ubuntu’s BOINC distribution. Fortunately, the fix is very simple. Just download the missing certificate , copy the file to /var/lib/boinc-client , then restart BOINC.