SiteServicesAddins.ReadFromPropertyBag: Site services addins don't exist for site collection

Oh man, this is an error that, when you see it, you'll be lost.  Here was out scenario:

Users would upload a document to a library in a Site Collection.  They would then try to tag that document with metadata.  We had four pieces of metadata, and the user would be able to tag them.

Then when the user clicked save, they would be told they don't have permission to update the document's properties, and two of the four metadata fields would not post. 

We would also see the following in the ULS logs:

CatalogConfig.ReadFromPropertyBag; Catalog configurations don't exist for site collection http://webapp/sites/collection

SiteServicesAddins.ReadFromPropertyBag: Site services addins don't exist for site collection http://webapp/sites/collection

At the same time, one of our admins recalled that they had deleted the Style Resource Readers group from the collection.

When that group is deleted, MANY BAD THINGS HAPPEN.  They are:

- Access Denied errors to a page
- Inability to browse menu items
- Inability to update metadata

So in our case, we re-created the Style Resource Readers group, gave NT Authority\Authenticated Users read permissions to the group, and made sure it had access to:

- The Style Library
- The Master Page Gallery
- The Site Assets Library

But still, we had the errors from above. 

After more digging, we found there is a list called the Hidden Taxonomy list that also is affected by this group.  This list holds Information Management Policy values when you set expiration on metadata.  The two fields the user couldn't update also happened to be fields that had expiration policies set on them.  So when SharePoint tried to invoke the policy to start it, the user didn't have rights to see what that policy was, hence the metadata was not applied.

That Hidden Taxonomy list lives at:  http://webapp/sites/collection/lists/hiddentaxonomylist

Once we went into that list and added the re-created Style Resource Readers group, we were back in business. 

The lesson here is be very careful who has Site Collection Admin rights, and make sure they speak loudly that they have maybe made a mistake.  It saved us a tremendous amount of time knowing a group was deleted that probably shouldn't have been. 

Then it was just an issue of finding something that was hidden.