The installation of object plugins silently fails if the Object Plugins directory is absent.
Steps to reproduce:
1. Open a file that uses one or more object plugins.
2. Open the Insert>Object...>Manage Objects dialog.
3. Perform an online synch.
4. Install updates.
Fix:
1. Create the missing directory indicated by Tools>Options>Folders>Object Plugins.
2. Then follow the steps above.