The Citrix ICA (Independent Computing Architecture) protocol is the language the client and server speak. A "Protocol Driver Error" means they started speaking, but one side stopped understanding the other.
Don’t panic. Most connection issues fall into four main categories. Here is your definitive guide to diagnosing and fixing them. citrix receiver connection issues
: It’s a cliché for a reason. Rebooting your computer and your router can clear temporary network glitches and stuck background processes. citrix receiver connection issues