Issue Summary

In rare circumstances the deletion of an object schema together with object creation can cause the deletion of the schema to fail and leaving some object types without attributes. 

Steps to Reproduce

1. Create an object schema with an object type and an object in it
2. Delete the schema
3. While the schema is deleting (after all objects are deleted) create a new object

Expected Results

The object creation fails because the object schema is being deleted. 

Actual Results

The schema deletion fails and standard attributes for an object type are deleted

Workaround

Once happened delete the schema again.