Update troubleshoot-resource-bridge.md

Author: alt-key

articles/azure-arc/resource-bridge/troubleshoot-resource-bridge.md

@@ -52,6 +52,11 @@ You may receive the following error while deploying Arc resource bridge: `Deploy
 
 This error typically occurs when trying to download the `KVAIO` image (400 MB compressed) over a network that is slow or experiencing intermittent connectivity. The `KVAIO` controller manager is waiting for the image download to complete and times out. You may want to check that your network speed between the Arc resource bridge VM and Microsoft Container Registry (`mcr.microsoft.com`) is stable and at least 2 Mbps. If your network connectivity and speed are stable and you are still getting this error, wait at least 30 minutes before you re-try as Microsoft Container Registry may be receiving a high volume of traffic.
 
+### Context timed out during phase `WaitingForAPIServer`
+When deploying Arc resource bridge, you may receive the error: `Deployment of the Arc resource bridge appliance VM timed out. Please collect logs with _az arcappliance logs_ and create a support ticket for help. To troubleshoot the error, refer to aka.ms/arc-rb-error   { _errorCode_: _ContextError_, _errorResponse_: _{\n\_message\_: \_Context timed out during phase _WaitingForAPIServer`
+
+This error indicates that the deployment machine is unable to contact the control plane IP for Arc resource bridge within the time limit. Common causes of the error are often networking related, such as communication between the deployment machine and control plane IP being routed through a proxy. Another cause could be a firewall closing access to the port.
+
 ### Arc resource bridge is offline
 
 If the resource bridge is offline, this is typically due to a networking change in the infrastructure, environment or cluster that stops the appliance VM from being able to  communicate with its counterpart Azure resource. If you're unable to determine what changed, you can reboot the appliance VM, collect logs and submit a support ticket for further investigation.