Is null and is not null operator are not working

See more:

Javascript

jQuery

Kendo

i'am using Kendo UI and in which i have data filter where many more filter operator are available there for example 'is greater than ' 'is less than ' 'is greater then or equal ' 'null' and is not null'
all are working but when i select the 'null ' and is not null' these two operator are throwing exception

exception is "This operator is not yet supported for this Grid"
if anyone has any idea of it please make me clear !

thank in advance :)

What I have tried:

All the filter options are working except 'is null' and 'is not null'