In all cases, these involved 32-bit LabVIEW running on 64-bit Windows 10. Since my post of six months ago, I've probably done a dozen install/uninstall/reinstall cycles, typically LabVIEW 2016, 2017, and 2018 (all three together), and recently I've added 2019 to the mix. I am currently working with NI Tech Support to document this problem and (I hope) to get them to work on a 'fix', as this is a very serious annoyance.

Once you have no NI Software on your machine, then reinstall what you want. if you have LabVIEW 2017 or later installed), I would strongly recommend that you not try to remove 'some' software, but instead remove everything, including NIPM (using the procedure that I outline). If you search the Forums for 'How to Safely Completely Remove LabVIEW 2018', you'll find my post for the procedure I'm currently running on my PC (I foolishly installed LabVIEW 2018 'on top of' LabVIEW 2016, which broke MAX and LabVIEW Services). I've done dozens of installations and un-installations, and I 'ruined' two Window 10 machines (I ended up reformatting the C: drive and reinstalling Windows, other software, and LabVIEW) before figuring out how to do it safely. With the introduction of the NI Package Manager in LabVIEW 2017, removing LabVIEW routines became much more difficult and fraught with problems.

How to uninstall multisim 12