ViewPlugValueWidget : Fix error handling
ViewPlugValueWidget : Fix error handling

andrewkaufman/gaffer,GafferHQ/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,johnhaddon/gaffer,andrewkaufman/gaffer,andrewkaufman/gaffer,johnhaddon/gaffer,GafferHQ/gaffer,GafferHQ/gaffer