https://support.office.com/en-us/article/outlook-freezes-clicking-the-signature-button-c70b36c2-66ca-401c-ab45-f29a46495d02

To workaround this issue, uninstall the pre-installed Microsoft Office Desktop Apps:

    Right click the Windows Start button and click Settings.

    Click Apps, and then click Apps and Features.

    Choose Microsoft Office Desktop Apps and click Uninstall.

    Restart your PC.