"No Internet Connection" on "Zoho Docs for Desktop" start

"No Internet Connection" on "Zoho Docs for Desktop" start

I've installed the Zoho Docs for Desktop https://www.zoho.com/docs/desktop-sync.html on my Windows Notebook, but when I start it I receive a error message "No Internet Connection", but my internet connection is working well for any other app and I don't use a proxy.

What can be the problem's reason ?

Regards,