For whatever reason when I use the formview with an inputoutput parameter I get a crazy error Cannot convert int to nvarchar...
After some investigation when checking the parameters collection it changes my return variable to a string even though it is an int 32
<asp:Parameter Direction="InputOutput" Name="Variable" Type="Int32" />
Datatype is string using e.command.parameters("@Variable")
To correct this - set the dbtype to the correct type in the SQLDatasource on Inserting Event
e.command.parameters("@Variable").DBType = DBType.int32