My fix for this issue was very simple. I have Product Design Collection, with multiple softwares on same machine.
In searching the C:\Programs Files\Autodesk folder for "adp_core" you will find multiple files in each sub directory for applicable software. I copied the local version of adp_core dll file from my NavisWorks folder. I assume you could choose any of these:

I then copied that file to applicable C:\Program Files\Autodesk\Vault Basic 2019\Explorer directory. No reboot or anything. Just try again, and it works. No errors at all.
Hope this helps others. Seems like the dll just doesn't come over to the needed directory for Vault.