Can you look in Boinc Manager at Tools / Computing preferences... and under the "disk and memory usage" tab confirm that "Leave applications in memory while suspended" is ticked. This could be why it isn't finding a last checkpoint and throwing up that error message. Worth a try.

Copied and pasted from an earlier answer:

On Rosetta this is usually solved by increasing the "use at most xxx% of CPU time" setting to 100. You may then want to reduce the "on multiprocessors, use at most xxx% of the processors" to something less than currently set. Most people find this handles the temperature regulation concerns (that the cpu throttling was designed to address) perfectly.

Another possible cause are virus scanners; most folks exclude BOINC from those scans or set it to run only when BOINC isn't active.

An explanation and more possible causes can be found here: BOINC FAQ Service

Please know that this only becomes a fatal error when it occurs 100 times to a particular task; at that point BOINC assumes the task will never be able to finish and gives up on it, ending it as a client error. If you see this message only occasionally it is safe to ignore it.


Best,
Snags