System.Err:Str (read/write)
Error message. If a command within a Try statement generates an error, the error message is stored in this variable. The Else part of the Try statement can therefore look at the message, or re-throw the error using Abort.
If a local variable System.Err is visible, the error message is stored in that instead of the global one.
Version Differences: In PCC 1.x, System.Err is a global property; the error message is always stored in the global property, and a local System.Err is ignored.
