KB485532: “Failed to start REST listener, please check if the REST port is in use.” error occurs when starting Intelligence Server in MicroStrategy 2021 Update 5.2

SYMPTOM:
 
In Strategy 2021 Update 5.2, “Failed to start REST listener, please check if the REST port is in use.” error occurs during Intelligence Server startup on Windows machine after reconfigure Intelligence Server without SSL as shown below:

Failed to start REST listener, please check if the REST port is in use.
The error might occur when following Knowledge Base Article has been applied:
How to Allow a Non-Administrator User to Start the Intelligence Server on Windows in MicroStrategy 2019
CAUSE:
 
The Intelligence was configured with SSL thus REST Server port 34962 is ready in use.
DSSErrors.log shows following errors:
[SERVER:CastorServer][PID:15392][THR:11748][RestWrapper][Fatal][UID:0][SID:0][OID:0][RESTListenerWrapperImpl.cpp:105] An exception was caught when opening the REST port, with details: ' Address 'http://*:34962/api' is already in use ', it stopped the starting of the REST Server.
 [SERVER:CastorServer][PID:15392][THR:11748][Network Classes][Error][UID:0][SID:0][OID:0][MSINetReactor.cpp:116] MSINetReactor::startRESTListen Shutdown I-Server now because it failed with following message: : 'Failed to listen on: http://*:34962/api'
ACTION:
 

Follow steps below to locate the URL reservation using the port 34962 and delete it. 

1.  Launch Command Prompt as Administrator 

2.  Run below command to identify URL reservation using the port 34962

netsh http show urlacl 

1.  Run below command to delete the URL. NOTE: The URL string should be exactly the same as identified in step 2

netsh http delete urlacl url=https://*:34962/api/

1. Now the I-Server started automatically.

Further Readings:
Netsh is a command-line scripting utility that allows you to display or modify the network configuration of a computer that is currently running. Refer to Microsoft official document for detailed usage.
3rd party warning:
Third Party Software Installation WARNING
The third-party product(s) discussed in this technical note is manufactured by vendors independent of Strategy. Strategy makes no warranty, express, implied or otherwise, regarding this product, including its performance or reliability.