Every time an entity is modified, those edits or additions are not stored in the Design Tool until the Apply button is clicked. Click Apply Changes in this dialog box to store your changes. If you want to delete the changes you have made, click Cancel Changes. If you are not sure that you are ready to store your modifications, click Continue Editing to close this dialog box.
Note: Applying changes does not save your modifications in the .model file. To save your changes, click Save on the Model menu.
Select the Don't show me this dialog again check box if you do not want to be reminded to apply entity changes.