The diagnosis tool shows current mine size parameters as well as informational and error messages produced by DLE during the various operation it has performed.

It also contains the mine checking function. If it is executed, all messages created by the mine verification tool are listed in the problem report list. When selecting an entry in the list, DLE will mark the corresponding mine elements to help in locating the problematic spot in the mine. If applicable, current segment, side, wall and trigger numbers will be updated appropriately so that these objects can be viewed in the corresponding tools.

You can have DLE automatically int problems it encounters. It will only int bugs where it makes sense and is safe to do.