Error message Exit Code 10, bytecount mismatch

Thanks for reporting this (both the problem and the solution).

A "bytecount mismatch" indicates that something goes wrong when writing the temporary output file at a checkpoint. It means that the file on disk has a different length than the program thinks it should have from the number of bytes it has actually written.

Both the error and the solution indicate that apparently something went wrong with the filesystem, probably somewhere down the C:\\Program Files\\BOINC directory tree. Just for the records: Is this an NTFS or a FAT32 filesystem? I'd rather suspect the latter.

BM