The terminal keeps asking for a code
Sign in first: a code attaches to an account. If you are signed in and it still asks, the licence has run out. Your Account page shows how long it runs.
A layer or a panel cannot be switched on
Point at it: it says what is missing. Usually the instrument has no data of that kind, or the layer is one of those switched off for now.
The chart says No footprint or Delta unmeasured
The range in view is older than the trade-by-trade data. Move towards the present, or open History to see how far back each kind of data goes.
An order was refused
The reason shown is the exchange's own. The usual ones are a size under the exchange's minimum, not enough margin, and a stop on the wrong side of the market.
A stop on MEXC is refused by the terminal itself, because MEXC does not hold stops through it.
A price alert did not fire
Alerts are watched only while the terminal is open. An alert that has fired stays on the chart, unarmed, until you arm it again.
A replay shows nothing
Recording was interrupted at that moment. Choose another: gaps are marked on the chart.
Test Connection fails
Check that the key was created for the same environment you chose, Live or Testnet; that it has permission to trade; and that the secret was pasted whole. The message shown is the exchange's own.