Zcash underwent a protocol upgrade on 28 October 2018 called Sapling.
In order to dispense or accept ZEC at your machine, you must be running the latest wallet version.
If you do not update from earlier versions, cash-in and cash-out transactions on ZEC will fail.
As always, it is important to back up your wallet, especially before making changes to wallet software.
Checking your version
You may check your current wallet version with:
If it is not v2.0.2 or above, update the Zcash wallet with the command below.
To update, run the script below:
curl -sS https://raw.githubusercontent.com/naconner/lamascripts/master/updates/nodes/zec.sh | bash
If successful, it will output 'Zcash is updated and running.'
Afterwards, verify that the earlier version command now outputs v2.0.1.
Additionally, check that the Funding panel in your admin displays your current balance.
Please contact firstname.lastname@example.org with any questions.