Are you still experiencing this issue kkiller-wolf ?
There are two cases where this can happen, 1. if you are logged out when trying to reply to a topic, or 2. you are trying to reply to a Classroom topic without a membership.
If neither of these are the case try logging out and back in to see if that resolves the issue. If it still continues after that, please reach out to us so we can look into it further. 🍪