Using the Clean command in XCode prevents the editor from opening

In XCode, if the Product->Clean option is used, the editor from the launcher will not open.

Workaround:
This can be fixed by running Verify from the Launcher.

1. Open UE4 4.10 from the Launcher
2. Create a new Code project
3. When XCode opens, select Product->Clean from the toolbar
4. When this finishes, click Launch for the 4.10 engine on the Launcher

Result:
Launch button disappears for a moment then returns but the editor does not open.