We had a user that cannot see all the web parts that are available on their site. They have Full Control of the site. I see them when I go to the site (but I’m the Site Collection Admin). The problem is when they try to add a webpart, under All Webparts, he gets “No webparts found” when they should have a list similar to the following:
The solution to this is to add the user to the root site collection with Read permissions. I know I know, what if you don’t want the user to have Read permissions to the root? Well that’s a question for Microsoft. However, this will fix it and allow work to continue.