The above worked perfectly fine for VectorWorks 2021. For me, this error started appearing after I updated to 2021 SP3. It also appeared multiple times every time I exported to MVR (kept having to click to close it, but it didn't seem to have a negative impact on the resulting MVR files). After ensuring VectorWorks isn't running and copying the three folders from C:\Program Files\Common Files\Vectorworks 2021 to C:\Program Files\Vectorworks 2021\Vision, the error did not appear again upon running VectorWorks.