Hi Ed;
WOW .. this sounds like this might be a PB 12.6 issue. 
BTW: I would check the atl71.dll, atl100.dll, msvcp71.dll, msvcp100.dll, msvcr71.dll, msvcr100.dll file sizes and dates on the redistribution package vs what PB 12.6 installed in its "shared" folder.
FWTW: Sounds like you might need to open a support case with SAP on this one.
Suggestion: Can you try a lower PB release - like 12.5.x? FYI: Many of my Canadian Government clients are in production & running solid using PB 12.5.1 currently. 
Regards ... Chris