Commented Issue: Error with MaskedEditValidator [26984]

When i try to use the MaskedEditValidator I get a NullReferenceException

That is the Call stack location

AjaxControlToolkit.DLL!AjaxControlToolkit.MaskedEditValidator.OnPreRender(System.EventArgs e ) Line 360 + 0X29 bytes

and Source file information:

Locating source for 'C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditValidator.cs'. Checksum: MD5 {ea 2f 74 58 2f 82 7f 77 98 d9 88 ba c4 e0 18 25}
The file 'C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditValidator.cs' does not exist.
Looking in script documents for 'C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditValidator.cs'...
Looking in the projects for 'C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditValidator.cs'.
The file was not found in a project.
Looking in directory 'C:\Program Files\Microsoft Visual Studio 10.0\VC\crt\src\'...
Looking in directory 'C:\Program Files\Microsoft Visual Studio 10.0\VC\atlmfc\src\mfc\'...
Looking in directory 'C:\Program Files\Microsoft Visual Studio 10.0\VC\atlmfc\src\atl\'...
Looking in directory 'C:\Program Files\Microsoft Visual Studio 10.0\VC\atlmfc\include\'...
The debug source files settings for the active solution indicate that the debugger will not ask the user to find the file: C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditValidator.cs.
The debugger could not locate the source file 'C:\Users\Stephen\Documents\Repos\Superexpert\AjaxControlToolkit\Server\AjaxControlToolkit\MaskedEdit\MaskedEditValidator.cs'.
Comments: I solved the issue. I had forgotten the ControlExtender property. But the error should be clearer.