I am setting the radgrid's datasource to my dataset. I wasn't using the DataBind()-function, but I tried inserting it after the datasource assignment and suddenly couldn't get to a hierarchy level above 2 even though i could before(and can if it is removed).
I've seen the links you've provided. I'm not sure if I can use them in the same way. I initially thought this was a generic problem, but it might be specific to my case. I have a rather large set of tasks. each task can have a subtask and each subtask can have another subtask(this extends to an arbitrary large depth). The way this hierarchy currently is implemented is that each task have a column containing their parent id, and the root of the hierarchy have null as a parent.
The current implementation, that gives the first mentioned error, is that I programatically create the dataset and the relations between the tables and then rebuild the entire grid. On an update I manually update my database with the the new values and build it again.
As mentioned earlier the application throws an exception if it is updated more than 1 time, what i find curious is that when the application is restarted the grid is updated and no new exception is thrown until 2 or more alterations have been made