This is a very old forum post but I figured I'd respond with my findings in case anyone else needs help on this.
I often times will use the address bar to navigate through folders (reference screenshot). In my testing I found that if I clicked "Projects", then before it finished loading I clicked "PDM Pro Vault", the error came up.
Pretty easy fix, just don't click on the folders too quickly.
There could be some other causes of the error but this is just one thing to keep in mind for the future. If the problem persists definitely contact your local Solidworks VAR.