How to resolve issues with slow patch downloads.
Problems with patching may be resolved by disabling the read-only setting on system folders.
Unable to install Battle.net Application after downloading from the website.
The Battle.net desktop app is trying to connect to an invalid or nonexistent server.
The Battle.net desktop app is trying to connect to an invalid or nonexistent server.
Troubleshooting steps for latency problems in Diablo III
Troubleshooting steps for disconnection issues when playing Diablo III.