There are many reasons for missing ribbon or toolbar, it could be incomplete installation of your CAD, or customization file corrupted. The following provides some of the solutions.

1. full-screen mode

The full-screen mode is on when using CTRL+0 and the ribbon and toolbar would disappear, shown as below, to restore the missing ribbon and toolbar, just press CTRL+0 again.

2. Try Reset

Enter OP and press Enter key, then find Profiles tab and select a profile, the default profile is Unnamed Profile, click the Reset button, shown as below,

3. manually load customization file

One of the reasons for missing ribbon or toolbar is that customization file has been removed, shown as below,

So to restore the missing toolbar, we can manually load the customization file by clicking Browse to specify the customization file to be loaded.

Use MENULOAD or CUILOAD to pop up the dialog box, and click Browse to load customization file.

If you don’t know your customization file path, just search gcad.cuix in your computer.