If the wallet is 1y+ old I'd recommend to recover the balance using your seed. Backup format changed since, but keep it just in case.

To do a quick try, enter the seed phrase into recovery of wallet.cashu.me - it automates some steps at the cost of less flexibility for complex recoveries, but usually worth to touch.

If it wan't brimg it back, you'll need to figure out which of the older keysets was used to issue your ecash and select it in Minibits wallet recovery tool - if you had long wallet history this may take some time to complete.

DM me about the progress. Thanks!