Restore of a database failed - Table does not contain an identity column
Do the restore using T-SQL with the RESTORE DATABASE ... statement - that should provide a more meaningful error. 

In brief, restore database works like this:

RESTORE DATABASE [database_name]
FROM DISK = N'\Path\to\the\backup\file.bak'
WITH RECOVERY
   , MOVE N'file name' TO N'new\path\for\this\file.mdf'
.
.
.


I wrote a blog post with code that automates creating the RESTORE DATABASE statement.  You simply point the code at an existing database backup file, and it will generate a valid restore command which you can then use to restore the database.

Using T-SQL to restore the database will provide a much more fine-grained set of error messages than using the SSMS GUI.

Also, I'd check the SQL Server Error Log to see if there are any pertinent details.  I also wrote a blog post with a quick script that can be used to show details from the Error Log.