Issue Reported: Application catalog error with IIS HTTP Error 503. The Service is unavailable. Getting below error.
Step 1: Validate component found that many error reported. Refer below screen shot for reference
Step 2: After validate verify IIS services look like application service was not running. Refer below screen shot for reference.
Step 3: Started Configmgr Service Portal Pool and validate component and web service it start working as normal.
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