# Why Is My Remote Session Interrupted by a Protocol Error?

#### Symptom

An error message is displayed indicating that the remote session will be disconnected because of a protocol error.

Figure 1 Protocol error

#### Possible Causes

The registry subkey Certificate is damaged.

#### Solution

1. In the Run dialog box, enter regedit and click OK to open the registry editor.
   Figure 2 Opening the registry editor
2. Choose HKEY_LOCAL_MACHINE > SYSTEM > ControlSet001 > Control > Terminal Server > RCM.
3. Delete Certificate.
   Figure 3 Deleting Certificate
4. Restart the ECS.
5. Choose Start > Administrative Tools > Remote Desktop Services > Remote Desktop Session Host Configuration.
   Figure 4 Opening Remote Desktop Session Host Configuration
6. Right-click RDP-Tcp and choose Properties. In the displayed dialog box, click General and set Security layer to RDP Security Layer.
   Figure 5 RDP-Tcp properties

Parent topic: Login and Connection