Read the error message: it couldn't be any clearer:
Error:No row can be added to a DataGridView control that does not have columns. Columns must be added first.
It's even telling you what you need to do first!
Quote:But I already created the columns in design, the same way I added columns in other dgv
Well, clearly not, or somewhere in your code you are clearing the columns out.
Start be checking that you have the right DGV: the name implies it's not created by the designer automatically (it adds a number to the end, and nobody sane renames a control from
so it's likely that you got it wrong.
If you have carefully checked, and are absolutely sure, then do a search for all references of the control and look to see where columns are added and if they are ever removed.
Sorry, but we can't do any of that for you!