a v2 wallet.dat should not be used with a v3 wallet
export the private keys that hold coins and import them into a new v3 wallet
This seems to have made the trick. However I still get the "Synchonizing sporks". It's been stuck there for a long time although the blockchain is up to date.
I didn't find anything referring to this in the FAQs.
are u on the same block as explorer shows?
if not check answer to Q18
https://chainz.cryptoid.info/dmd/even if u on correct block u could try delete everthing beside wallet.dat blocks and chainstate folder
this way u keep the synced chain and ur wallet but everything else is created new at start