Report Configuration changes
As you can see from the definition you provided for [dbo].[ConfigData], both Value and ValueInUse are defined as SQL_VARIANT data types.  The error message you are receiving is:


  Msg 257, Level 16, State 3, Procedure usp_SysConfigReport1, Line 19
  Implicit conversion from data type sql_variant to int is not allowed.
  Use the CONVERT function to run this query.


So Value and ValueInUse are SQL_VARIANT (as also are the derived values for OlderValue, OlderValueInUse, RecentValue, and RecentValueInUse) but you want to use them as INT.

The error message is saying that you need to change the SQL_VARIANT into INT by using the CONVERT function.  An example of selecting a SQL_VARIANT and turning it into an INT. 

SELECT CONVERT (int, Value) FROM [dbo].[ConfigData]


The CONVERT changes the datatype (if possible) from SQL_VARIANT to INT.

Just make sure to CONVERT to the proper data type and all should be well.