Gotcha. I have used the term AV primarily when referencing "audio/visual".
In my case, Windows Defender did not seem to be the issue as simply reinstalling fixed the issue.
Thanks.
I have multiple instances of BI. I upgraded 3 of 6 to v6 and this error happened on two of them. Reinstalling AImodelpack.exe made it go away. One of the two I had to reinstall 3 times before it finally went away.