Error in the 2X log:
TS Agent hostname: [E 08/00000013] Failed to enum printers (The RPC server is unavailable. [0x000006ba])
This error is different from the other, more typical errors related to printer redirection where the driver is missing. This error is inidicating a problem with the 2X Universal Printer driver.
Running a repair install of the Universal Printer driver resolved this problem.
C:\Program Files\2X\ApplicationServer\UniversalPrinter\x64>2XUnivPrnInst.exe /R