SecurityAction.RequestMinimum is obsolete in .Net 4.0

Question

Recently, our .Net client libaray is upgrading to compile against Net 4.0. After change the target framework to 4.0, the application has some compilation error.

In

Answer 1

Some searching led me here for a similar VB.net rdlc error (so yes, I know the question was tagged C#). I did not utilize the offending code, but I did find that a stray underscore caused this error, for example: in a textbox expression you might accidentally put:

"This is a " & _
"test"

thinking you are in some code behind, but alas this generates this same error as listed above and once removed, the error was gone.