The Client Errors are from sanity checks in the program, meaning that something is happening that should not be possible (the calculations we do could not yield infinite numbers, and an index into an array could not be negative). Also a result that is sent back from a run where the App didn't crash (i.e. that was "successful") may contain wrong numbers (or values that are not numbers at all).
Errors of this type most likely point to an overheated CPU, possibly during the hotter days of the year. Other hardware problems are also possible (heat related or not), but they are by far less common.
BM
