How to debug pop-up window

The okcode field is deactivated when a modal window (the technical name of popup windows) is displayed, so it seems impossible to enter the debugger (using /H okcode).

In common dialogs, the okcode field is available, so you can type /H to enter debug mode:

however,  it is not available in modal windows (we see it but we can't enter anything in it):

The solution is to create on the frontend a SAPGUI shortcut (file with extension .SAP), of type System Command and command /H, and drag and drop it from Windows desktop to the SAP modal window. You can create the SAPGUI shortcut as explained here:

- Click on the Create shortcut icon on a the toolbar in a SAPGUI session

- In the popup window enter teh values you need, in this case Type = System Command and Command = /H

- Press Finish and a shortcut on the Desktop (or the location you entered) will be created