You can create the TileCollection manually using SaveAs from the infodba-TileCollection Call it Site-TileCollection.
From GTAC How to Reset a User's Home Page (aka Gateway)
If an important Tile is accidently unpinned, it can be restored using the RAC or dhtml client.
The simplest way to do this is to revert the user's home page to use the default for their Site/Group/Role. When this technique is used, the user will lose all personal home page customizations.
1. Launch RAC or dhtml client. 2. Search for the user's Tile Collection using General... query: type: Tile Collection, owner: <user>) the name will be like <userid>-Tile Collection 3. Delete the Tile Collection.
The next time the user accesses their home page, a new Tile Collection will created for them based on their Group and Role.
If instead, finer-grained control is needed, the following technique should be used. For example, the user has accidentally unpinned their Inbox, but they have other pinned objects that they don't want to lose.
1. Launch RAC or web client. 2. Expand the Tile collection. 3. Search for the user's Tile Collection (as above). 4. Select the inherited Tile to restore, select: Edit -> Properties On Relation... 5. Mark the "Hidden" property as non-hidden