Avast has instructions for modifying Blocked and Allowed apps here. https://support.avast.com/en-ww/article … ed-apps#pc

Thanks Tom, that seems to have done the trick. Not quite sure what I did, but by following your link and playing around with a few settings here and there, then trying to open a project in MVPX6, in hope rather than expectation, the project opened up just fine without that annoying message. Thanks once again.