I can successfully use Print Management to print/e-mail Sales Order Invoices when I do NOT run as a batch.
But if I enable batch, then SOME of the records will send successfully (both print and/or e-mail) but will fail part way through with the following error message:

ANY suggestions or thoughts, no matter how crazy they may sound are welcomed at this point. Here is some general information about the setup:
-AX 2012 R3 CU 8
-3 AOS's using RD web access for client connection
Things I have tried:
- Running the batch on different AOS's
- Running the batch with only 1 thread (eliminating multithreading)
- Running the batch at different times
- Running the batch without also posting the invoices (using Print Management after invoice posting)
- Running in a Dev and Test environment restored from Production (These run successfully)