This dialog appears when the tree capacity limit has been reached during a refresh operation of the tree.
For each type of tree, the number of nodes that the tree can contain, or its capacity, may be set to a default or custom limit.
Every time the tree is refreshed, the tree capacity limit will be checked. If the capacity must be increased to accommodate the change, then this dialog will ask the user for permission to do so. The new capacity is permanently stored for subsequent use.