A) During tutorial, open chat before a tutorial prompt appears. The prompt cannot be dismissed with [Tab], and the chat cannot be closed with [`]. The only way to progress is pressing [Esc] to close the chat, after which [Tab] can dismiss the prompt.
B) Same situation with normal windows, except there are more ways to escape (describing it here because it seems similar enough):
- open a window (inventory, production, etc.)
- open chat with [`]
- click in GUI (so that chat loses focus)
Related to, or duplicate of viewtopic.php?f=48&t=92530, but I couldn't figure out whether this case is described there.