A permission manifest is a list of permissions.
The permission manifests are maintained automatically. Just occasionally, however, they need to be triggered to recalculate.
The portal has a single permission manifest for the fixed parts of the portal, and an additional component called the permission manifest manager which manages a permission manifest for each repeating item, such as folders and tasks.
Permission manifest
Refresh this to fix problems such as users being unable to see the portal at all.
Go to Advanced settings and select the Permission manifest page.
From the drop-down in the top right, select the ... More option. This opens up a properties panel.
Select the Recalculate option.
This will refresh all the permissions in the manifest.
Permission manifest manager
Even if there are problems, you should not need to refresh this. Most permission problems are to do with folders and tasks, and you can fix these more effectively using the Refresh all option described in Folders followed by the Refresh tasks option on the Home folder, also described in Folders.
If there are still problems, you can attempt to refresh all the permission manifests
Go to Advanced settings and select the Permission manifest manager page. Use the Refresh manifests button to refresh all the permission manifests. This may take some time.