Also, from WebConsole.log Im getting the following with lot of ERROR, WARN, Unable & Failed

 1 06/29 20:29:13    ERROR DefaultHandler:?:? - Web service status: RESPONSE_ERROR
 2032 9 06/29 20:29:13 fe80:0:0:0:2090:3b6a:9370:98fa%5   ERROR ServerUtil:?:? - Failed to load all server properties as an exception was thrown. Web service is not available: state=RESPONSE_ERROR
  1 06/29 20:30:37    INFO  LogbackConfigBase:log:81 - Retrieving configuration properties using global params API
  1 06/29 20:30:37    INFO  LoginService:makeNewDummyLoginCred:167 - Performing dummy login for user- _+_PublicSharingUser_
  1 06/29 20:30:37    WARN  ServerBroker:?:? - Invalid response returned: 500
  6 06/29 20:33:09    WARN  ServerBroker:getResponseAndHandleExceptions:500 - Invalid response returned: 500
  6 06/29 20:33:09    ERROR ServerUtil:getSSOEnabledDomains:448 - Unable to load domain information. INTERNAL_SERVER_ERROR
  6 06/29 20:33:10    INFO  BlockableApplicationsService:?:? - Configuring BlockableApplicationsService
  6 06/29 20:33:10    INFO  BlockableApplicationsService:loadBlockableApplicationList:175 - Loading application rules file: applications.json
  6 06/29 20:33:10    ERROR BlockableApplicationsService:?:? - Failed to determine installed SP due to exception. Assuming new installation.
 java.lang.NullPointerException: Cannot invoke "javax.servlet.ServletContext.getAttribute(String)" because "servletContext" is null
    at commvault.web.core.ServerUtil.getCsGuid(ServerUtil.java:1666)
    at commvault.web.core.ServerUtil.getCsGuid(ServerUtil.java:1662)
    at commvault.web.core.ServerUtil.doDummyLogin(ServerUtil.java:1701)
    at commvault.web.core.ServerUtil.doDummyLogin(ServerUtil.java:1694)
    at commvault.web.core.ServerUtil.prepareRequestWithDummyLogin(ServerUtil.java:796)
    at commvault.web.core.util.AppSpecificUtilImpl.getCsInstalledSp(AppSpecificUtilImpl.java:54)
    at commvault.web.core.util.AppSpecificUtilImpl$Proxy$_$$_WeldClientProxy.getCsInstalledSp(Unknown Source)
    at commvault.web.core.blockapplicationservice.BlockableApplicationsService.getCsInstalledSp(BlockableApplicationsService.java:131)
    at commvault.web.core.blockapplicationservice.BlockableApplicationsService.determineAndSetOldInstallation(BlockableApplicationsService.java:116)
    at commvault.web.core.blockapplicationservice.BlockableApplicationsService.updateSettings(BlockableApplicationsService.java:104)
    at commvault.web.core.blockapplicationservice.BlockableApplicationsService.init(BlockableApplicationsService.java:90)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.base/java.lang.reflect.Method.invoke(Unknown Source)
    at org.jboss.weld.injection.producer.DefaultLifecycleCallbackInvoker.invokeMethods(DefaultLifecycleCallbackInvoker.java:83)
    at org.jboss.weld.injection.producer.DefaultLifecycleCallbackInvoker.postConstruct(DefaultLifecycleCallbackInvoker.java:66)
    at org.jboss.weld.injection.producer.BasicInjectionTarget.postConstruct(BasicInjectionTarget.java:122)
    at org.jboss.weld.bean.ManagedBean.create(ManagedBean.java:164)
    at org.jboss.weld.contexts.AbstractContext.get(AbstractContext.java:96)
 10 06/29 20:33:10    WARN  ServerBroker:?:? - Invalid response returned: 500
  10 06/29 20:33:10    ERROR ServerUtil:?:? - Unable to load domain information. INTERNAL_SERVER_ERROR
  3 06/29 20:33:10    WARN  ServerBroker:getResponseAndHandleExceptions:500 - Invalid response returned: 500
  3 06/29 20:33:10    ERROR ServerUtil:getSSOEnabledDomains:448 - Unable to load domain information. INTERNAL_SERVER_ERROR
  7 06/29 20:33:10    WARN  ServerBroker:?:? - Invalid response returned: 500
  7 06/29 20:33:10    ERROR ServerUtil:?:? - Unable to load domain information. INTERNAL_SERVER_ERROR
  1 06/29 20:40:38    INFO  LogbackConfigBase:log:81 - Retrieving configuration properties using global params API
  1 06/29 20:40:38    INFO  LoginService:?:? - Performing dummy login for user- _+_PublicSharingUser_
  1 06/29 20:40:38    WARN  ServerBroker:getResponseAndHandleExceptions:500 - Invalid response returned: 500
  1 06/29 20:50:38    INFO  LogbackConfigBase:log:81 - Retrieving configuration properties using global params API
  1 06/29 20:50:38    INFO  LoginService:makeNewDummyLoginCred:167 - Performing dummy login for user- _+_PublicSharingUser_
  1 06/29 20:50:38    WARN  ServerBroker:?:? - Invalid response returned: 500

Does the behaviour change if you perform an "iisreset" from the commandline?

Hello @Jos Meijer  and thanks for your reply!

Tomcat and iisreset are not worked for me, but after troubleshooting and research in similar previous threads in community, I found the solution.
 

My issue was in dotnet core version! CS and temporary CS has different dotnet core version.
I followed these steps and after that Command Center are opened without any issue.

• Check you current version of dotnet with command: dotnet --list-runtimes
• Download it from MS site by selecting just the link for Hosting Bundle: https://dotnet.microsoft.com/en-us/download/dotnet/3.1

• Clean any other versions of .NET CORE (not Framework) that could be installed.
• Use downloaded media to install or repair .Net Core. It should end up looking like this (Note that it has 3 components):

• Finally, restart IIS services by running iisreset command from cmd.

Good to hear you found it and thank you for sharing the details