SQL Server Stored Procedure Errors

I can't figure out how to get Mirth to register messages as an error if the calling procedure raises an error. When I run my Store Procedure with SQL Management Studio, I get the following output:

Code:

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Msg 245, Level 16, State 1, Procedure insertData, Line 742

Conversion failed when converting the nvarchar value 'U' to data type tinyint.

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Unfortunately my Mirth setup doesn't see a problem with this and continues on it's way.

SQL Server Stored Procedure Errors