Some submission types are not displayed in the "PC Online Forum"

Some of the submission types are not displayed to program committee members in the "PC Online Forum"

For example, full papers and short papers are shown, but posters and demos are missing.
What has happened?

The respective submission types have been disabled for the forum.

Please go to:
Overview => Settings => Manage Submission Types / Conference Tracks
Select a track/type of submission here and click the button "Edit".

On the page opening now you will find under "Review Options" the option "Online Forum for the Program Committee".
The default setting is enabled, so someone disabled it.

Please re-enable it and save your settings.