If you use Ubuntu 16.04 LTS or lower and you are unable to open the Zoho Meeting Desktop app, please follow the steps mentioned here first. Additionally, you need to update your outdated Network Security Services library by following the steps given below.

1. Open 'Software Updater', then click Settings.

2. Check the box for 'Important security updates (xenial-security)' and click Close. This will update your cache.

3. Open the Terminal app and the run the command 'sudo apt-get install libnss3'.

4. Enter your system password when prompted to continue with the update, and try opening the desktop app.