You can fix this error in two ways:
There are two ways to solve the error:
Depending on the behavior you want use one of them. Good luck!
Select the invoke button and set 'click event button' on to 'true' in the properties bar. The error will disappear. You removed the 'Edit' button, so there is no selection button when the 'click event' properties of the datagrid are set to 'Edit'. If you set the 'click event' properties of the datagrid to 'Edit', there should be one button with the 'click event button' set to 'true'. This won't happen if the 'click event' properties are set to 'Return selected' or 'Do nothing'.