Unable to access Windchill Application with HTTP Response Code 403 error in Windchill PDMLink

• Unable to access Windchill Application with HTTP Response Code 403 error post CPS Update

The server understood the request but refuses to authorize it

• Windchill wt.auth.Authentication command fails with below error

DEBUG [main] wt.httpgw.HTTPLogin - Opening URL connection to https://<servername.domain>/Windchill/servlet/WindchillAuthGW/wt.httpgw.HTTPAuthentication/login
DEBUG [main] wt.httpgw.HTTPLogin - Unexpected content type: text/html;charset=utf-8
DEBUG [main] wt.httpgw.HTTPLogin - Failed to get input stream from connection
java.io.IOException: Server returned HTTP response code: 403 for URL: https://<servername.domain>/Windchill/servlet/WindchillAuthGW/wt.httpgw.HTTPAuthentication/login

• After upgrade server fails to connect via remote web server
• After Rehost scenario, fails to access Windchill
• After Critical Patch Set (CPS) update, cannot access Windchill UI 
• Method server error

ERROR [wt.intersvrcom.SiteMonitor.pinger] wt.intersvrcom.SiteMonitor  - Names=[Site_Asheville], URL=https://<hostname>/Windchill/servlet/WindchillGWQA, Status=SITE NOT RESPONDING, ResponseSeconds=0.006, TimeOfPing=xxxx-xx-xx  xx:xx:xx.xxx -0400

ERROR [wt.intersvrcom.SiteMonitor.pinger] wt.intersvrcom.SiteMonitor  - Names=[master], URL=https://<hostname>/Windchill/servlet/WindchillGW, Status=SERVLET ENGINE NOT RESPONDING, ResponseSeconds=0.269, TimeOfPing=xxxx-xx-xx xx:xx:xx.xxx -0400

• Seeing an error in Access.log

127.0.0.1 - - [xx/xx/xxxx:xx:xx:xx +0000] "GET /Windchill/servlet/WindchillGW/wt.httpgw.HTTPServer/ping HTTP/1.1" 403 618 2468
127.0.0.1 - - [xx/xx/xxxx xx:xx:xx +0000] "GET /Windchill/wtcore/test/dynAnon.jsp HTTP/1.1" 403 618 1630

• Failed at UpdateContainerTemplates task during upgrade, upgrade log throws below log

2023-09-06T12:42:49,215 ERROR [main] com.ptc.windchill.upgrade.statemachine.state.PhaseEventUpgradeState - Upgrade execution failed with the exception:
wt.util.WTException: (com.ptc.windchill.upgrade.util.utilResource/12) wt.util.WTException: Unable to complete startup of all Windchill Service

• Unable to log in to Windchill with following browser error on Windchill Single Sign (SSO) configured Server

https://<Windchill_hostname>/Windchill/sso/shibboleth/sessionHook?return=https%3A%2F%2F<Windchill_hostname>%2FShibboleth.sso%2FSAML2%2FPOST%3Fhook%3D1%26target%3Dss%253Amem%253Aa2990408f0626e8c92e550f02c06e46a7db4c5ac7bdefaf3a1f42c21d8bbf80d&target=https%3A%2F%2F<Windchill_hostname>%2FWindchill%2Fapp%2F
HTTP Status 403 – Forbidden
Type Status Report
Description The server understood the request but refuses to authorize it