There are a few possible explanations for why your student(s) can't post. First, the
student(s) might not be in a group. Go to the Participants page (Course Dashboard
> Participants) and scroll to the student. It should list the group(s) they are in
under the Groups column. If they are not in a group, click the pencil next to "No
groups" and select the desired group from the dropdown. Then click the Save icon on
the right. If they are in a group, did you set the appropriate grouping in the forum
settings? If not, do so. If you do have it set to the appropriate grouping, it might
be that the groups are not associated with that grouping. For either, please see our
help guide on how to Create Groups and Groupings.
The other possible explanation is that you set your forum type to the Q&A Forum Type,
but did not post any questions. When using a Q&A Forum Type you, the instructor, must
post first. You are posting the "question." Students then come in and reply to your
question with their "answer" (hence the name Q&A). Students cannot post questions,
so if there are no questions posted, students are unable to post in the forum. Question
posts are not brought over when importing or restoring course content, so they will
need to be re-posted each term. You must post the question to each group for the students
to be able to answer.