I remember seeing a discussion in the past where someone had the same issue and I recall they had to connect to the new database to get the data and then reconect to the vbulletin data to continue on.
I am not sure that this really helps much but I tried to find the thread and here are a few other topics that might help:
https://vborg.vbsupport.ru/showthrea...nnect+database
https://vborg.vbsupport.ru/showthrea...nnect+database
I will have to look more as I recall there was a thread on here that described how to do it but I have not found it.
Good Luck & please share your fix if you find one as I don't have an immediate use but I could find one!