Normally, we recommend checking for any anti-virus/firewall blocking access to Splashtop servers.
- Allow access to *.api.splashtop.com servers
- Allow access to *.relay.splashtop.com servers
- You can run a check tool, www.splashtop.com/check
- Even if this passes, make sure TLS tunnel containing non-HTTP traffic is allowed over port 443
Some customers have found that a Windows10 update, KB4056892, blocks Splashtop communications. Please uninstall this KB update for now.