Solving SQL Server Integration Services Expressions using Expression Builder is a bit of a chore until you have a good understanding and a few working examples of some useful expressions. Here are several common exceptions you might see when working within Expression Builder as well as examples and explanations of correct syntax.
Cannot convert System.Int32 to System.String
Here are a couple more exceptions you may come across:
“Cannot convert expression value to property type.”
“Cannot convert ‘System.DateTime’ to ‘System.String’.