So which error? - what you do here makes no sense to me... - a generic type that represents a list (hard to know from your naming) that contains a generic list of the same type - is this what you wanted?
But anyway I guess that your problem is just the declaration of RemplirDataGridList - it has to be the same (
) - come on, really read the .NET naming conventions! - as you declared you
instance so it's:
public void RemplirDataGridList<t>(DataGridView DG,clslistes<t> Lcls)
naming conventions for NET.
(I'm not joking: programming is inventing and remembering names - from all years of my experience, this is the most important thing I would say to be successful in programming...)