Updated from 1.9.6 to 1.9.9 and now BTC balance is 0

Some sections of my wallet appear to be intact but things like history transactions and balance are blank.
Please help. Not really a techie

Updating Bisq, which is just installing a new version, should not modify your wallet.
Are you sure you have balance before? And checked if there is connection and the wallet is in sync with the last Bitcoin block?