RDP error: Connection fails with "An internal error has occurred"

Issue

When you connect to another device using Remote Desktop Protocol (RDP), you receive the following error message: "An internal error has occurred."

Cause

The Microsoft security update (KB4103727) that addressed CVE-2018-0886 will prevent devices patched with this update from communicating with unpatched devices.

Resolution

Either update the unpatched device or create a Group Policy rule that reverts this change as shown in the Microsoft article for CredSSP updates for CVE-2018-0886.

You can verify that an unpatched device experienced this issue by looking at its event logs in Windows. Look for Event ID 6041.