I'm running an M1, but without the problem you describe. If I were, I would reset the project and re-install BOINC, and try again.

I have run GFN-21 tasks with 4 threads several times. They took over 5 days, but they ran successfully. For the current challenge, I am running with 3 threads in order to keep temperatures down and still finish in time. So far, so good.

If you run single threaded, be prepared to wait nearly three weeks for results.

This is profoundly embarrassing. My mt-3 task also failed, with messages similar to yours.

I went back to my benchmark results from Sep 27 and discovered that those successful runs were, in fact, single threaded. They ran in ~558,000 seconds, running four tasks simultaneously. (Between then and now I lost sight of that, and prepared the M1 for multitasking along with all the other machines, that are Intel.)

I apologize for leading this discussion astray, but it looks like multi-threading is not emulating well on the M1 processor.

"Using SSE4 transform (3 threads)"

"atos cannot load symbols for the file genefer_macintel64_3.3.4 for architecture x86_64.
xcode-select: note: no developer tools were found at '/Applications/Xcode.app', requesting install."