This works:
Exit neutron wallet program.
Delete everything in data directory (search for %appdata%) except wallet.dat and any "conf"-file.
I you have a "conf"-file edit and remove all "addnode=".
Start neutron wallet again but don't unlock it yet.
Let the wallet synch to the latest block.
Compare the block that the wallet have as the latest with the blockexplorer.
http://neutron.blockview.space/Save everything in data directory to a new backup directory except wallet.dat, peers.dat and any "conf"-file.
Start staking with the wallet by unlocking it.
When the wallet for some reason isn't synchronised with the latest block according to the block explorer. Delete again in the data directory as stated and copy the data from the backup directory to your data directory which gives a fast synching to the latest block.
I wonder if the new wallet has a higher version number and if it checks that nodes have the new wallet.
it doesn't check obviously.
and a lil easier advice to everybody: always delete peers.dat after you close the wallet.