Please do not ask for support on GitHub, GitHub is for code/project-related questions. Ask for support in the Discord server: https://discord.gg/DKu7cUZ4XQ.
To answer you anyways, it could either mean:
The server is down, try it again within the next 2 hours (restart the app before trying again)
Your device or network is blocking peer-to-peer (p2p) connections, try it again on another device or network, on a VPN, or ask someone else to download it for you on the Discord server
When I click on download in the android app, I get 'Network Error'. But the Internet is fine.