HELP PLEASE! Could not find and non-coinbase UTXOs to spend

Hi guys. Installed the ZCASH wallet earlier this week. Using a mining pool, ZEC coming into my T-ADDR via the mining pool (btw flypool.org has been great.).

Was able to successfully deposit twice to Poloniex without issue. Now, using the exact same command, I get
"Could not find and non-coinbase UTXOs to spend" when I do a z_getoperation result.

getinfo shows a balance, getunconfirmedbalance shows 0

What happened? How do I fix this? Any help appreciated, thanks