What does "Current screen is not synchronized with Host" mean?

The flow expected a specific terminal screen, but the host presented a different one (or the buffer had not settled yet). The method and the live session are out of step.

This message is from Screens Flow Methods (and the same engine when you run Play Flow in OL Terminal). It is not an emulator disconnect.

Check, in order

1. Screen identifiers (protected text that uniquely marks that screen).
2. Whether a popup, error, or extra menu appeared that the flow does not handle.
3. AID and timing — the host may still be painting when the next invoke runs.
4. Entry point — firstScreenId / login subflow must leave the session on the screen the main method assumes.

Fix the flow (identifiers, conditions, wait/navigation), then re-test. In OL Terminal, use Play Flow debug (step BEFORE/AFTER) to see which step first diverges.