MECM Client Windows Updates Scan Failed with Error = 0x80244022

Today, I was informed by a customer regarding an MECM (Microsoft Endpoint Configuration Manager) updates deployment issue. Some machines haven't downloaded updates for months. 

To troubleshoot the issue I examined logs related to software updates in client.

I noticed that in WUAHandler.log there is an error: Scan failed with error = 0x80244022.

When I clicked the error code the description was Same as HTTP status 503 - the service is temporarily overloaded.

Usually HTTP status 503 in MECM means WSUS app pool has stopped because of the insufficient private memory. I checked in IIS manager whether this is the same issue. But there was not any issue with WSUS app pool. It was up and running.

Then I tried to connect to WSUS in MECM from the client machine by going to below address from a browser.

http://<FQDN of MECM Server>:8530/selfupdate/wuident.cab

But it returned an error.

Then I checked proxy setting of that machine and added exception for MECM server.

Internet Explorer > Internet Options > Connections > LAN Settings > Advanced > Exceptions

Or else can add an proxy exception by command prompt.

netsh winhttp set proxy <ProxyServer:Port> "MECM Server FQDN"

Again I tried to visit above URL  and was able to download the cab file. After that I initiated the scan from client and it started to display deployed updates.