Q:

UriFormatException does not exist in .NET for Windows Store apps

Any idea how Uri. EscapeDataString() can throw a System. UriFormatException but it does not appear to be possible to catch it explicitly? 
If I try to catch it explicitly I just get "type or namespace name 'UriFormatException' does not exist in the namespace 'System'"

A:

According to Uri constructor help in MSDN:

In the .NET for Windows Store apps or the Portable Class Library,
  catch the base class exception, FormatException, instead.