This Knowledge Base article describes the situation when object editor (like attribute or metric editors) opens off-screen and makes the Developer window inactive/freezed. This article describes the solution of that issue. This can happen in Windows environment when user is using two monitors or a monitor+projector.
Developer window is inactive/freezed after opening object editor
One might notice that the editor is opened, but on this virtual monitor B, that is no longer connected. An icon on the task bar shows open editor, but it is impossible to activate it.

The position of the object monitor is being remembered even after monitor B is disconnected.
Option 1
Open Developer and object editor with two monitors connected. Move attribute editor from screen B to screen A and close everything on screen A, so this configuration will be remembered. Disconnect monitor B.
Option 2
Other solutions can be found in the Internet with the phrase "move window from off screen"
KB221994 KB442121