Getting error "Object reference not set to an instance of an object" while creating object of lique class"

That isn't Linq: it doesn't use Linq syntax, or Linq methods.

Instead, the problem is likely to be in the constructor for the TextDataContext class - so you need to look at that in the debugger and find out exactly what it is doing.

We can't: we don't have access to your code or any of the data on which it depends.