Occasionally on gateways when I try to relaunch a gateway that was closed previously I'll receive the following error:

C3 Host: Docker container based on the mcr.microsoft.com/dotnet/core/aspnet:2.1-bionic image
Gateway Host: Separate Windows 10 1909 connected to the C3 instance
Channels: So far I've gotten the error with both OneDriveRest and Slack channels.
I've run process listings confirming that the gateway process is no longer running, and the C3 UI gateway indicator is yellow.

In response, I usually have to create a new gateway and start from scratch.