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Power Monitoring Expert - Web applications 503 Service Unavailable Error

Issue
When opening Web Applications, a "503 Service Unavailable" error is displayed.

Product Line
Power Monitoring Expert 9.0
Power Monitoring Expert 2020
Power Monitoring Expert 2021
Power Monitoring Expert 2022
Power Monitoring Expert 2023

Environment
Web Applications
IIS Manager

Cause
A potential cause for this error is when an application or a process is using port 80 (HTTP) or port 443 (HTTPS). This results in the Default Website in IIS being stopped, and when starting it manually the following error is prompted.
IIS Error

Resolution
1. The following netstat commands can be used in command prompt to retrieve the Process ID (PID) of the application/process that is using port 80 or 443. In this example, the PID of the process that is using port 80 is 5484
netstat -aon | find ":80"
netstat -aon | find ":443"

2. The result will be similar to the information shown below:
CMD Prompt Result
In this example, the PID of the process that is using port 80 is 5484.

3. The process associated with this PID can be found in the Task Manager Details tab (can be ordered by PID). In this example, this PID belongs to Skype.

4. Once the process/application is identified, (if possible) it can be temporarily ended from Task Manager (right-clicking and selecting End Task). Confirm if the Default Website in IIS Manager can now be successfully started which then results in Web Applications returning to normal operation. If this is the case the identified application (in this example Skype) needs to be configured to deploy another port.