InstallShield 2018- Windows 10 LTSB-N

ISDBG.exe fails with "Failed to create empty document"

I have ISDBG.EXE & SciLexer.dll in the same folder, IS-Debug. I have installed the MSVS2012 SP4 runtime and rebooted. I am able to register ISDBG.exe because it opens with this command: setup.exe /d"c:\is-debug". I have all the files including the 2 mentioned above in the same folder.

I can open ISDBG.exe and select menu Open and get the same error. I have read the other threads and I think I have covered all the suggestions in those threads.

Any suggestions what to look at next?