Yes after the failure the funds are still visible in the z-address, I only shielded my mined funds to the z-address.
Did you leave room for the fee by subtracting 0.0001 from the total, or send much less than the amount?
Tested it with all possible amounts, even with only 1 VRSC it shows this error message.
Can you try the following:
1. Close the wallet software
2. Backup your wallet - on Windows, it is in \Users\
3. Delete everything in that VRSC directory, except VRSC.conf and wallet.dat (it should be fine, just good to backup before deleting anything in that directory)
4. Reload the wallet and wait until sync
5. Confirm your balances
It's likely that will solve the problem, and if so, you had some corruption in your local chain state.