When working with content, you find yourself unable to perform any or all of the following actions:
1. You can not edit the content
2. The content cannot be deleted
3. The content remains in a submitted state regardless of what you do to it.
4. You may see an error like "object reference not set to an instance of an object" when accessing the content
A telling sign is that the content displays an odd status of 'M' or 'S'
Typically, if you're having trouble with certain content, the main reason tends to be related to that item being "stuck" or in a bad status.
This issue is pretty easy to correct however. Please refer to the KB article, Content not checking in using the workarea for instructions detailing how to change the status of a content item back to A.