Here is additional information from Knowledge Center :
What does "Z" denote in FID 118 for US Stocks?
The letter "Z" in FID 118 for US Stocks denotes that there is a trading halt for this company (which can be seen in FID 40). This means that the company cannot trade for the entire day until the exchange sends the message to resume trade the next day.
"No Open" or "No Resume" means that the company cannot resume trading till it is confirmed by the exchange.
A trading halt is a temporary suspension in the trading of a particular security on one or more exchanges, usually in anticipation of a news announcement or to correct an order imbalance. A trading halt may also be imposed for regulatory reasons. During a trading halt, open orders may be canceled and options may be exercised.
Read more here Investopedia: Trading Halt
As this message does not look to be neither API nor distribution infra (TREP) generated, the best way to investigate this would be with TR content, via Raise a case or by calling TR support.
If you can include the complete message, we can review some developer materials on my side. Each exchange is different, they publish halts differently. My first stop would be Knowledge Center on TR Customer Zone