Running the attached file in E+ 9.1 gives:

** Severe  ** AirLoopHVAC:UnitarySystem = ASHP UNITARY SYSTEM
**  Fatal  ** getUnitarySystemInputData: previous errors cause termination. Check inputs

But there are no previous errors. By running it through the debugger, we eventually discovered it was caused by the AirLoopHVAC:UnitarySystem's Heating Supply Air Flow Rate accidentally being set to zero. Seems like the error message is missing?

There is an error message in the code but it's commented out.

in.idf.txt
eplusout.err.txt