Unable to Communicate to the PPM server error with client side exception in app-ca.logs

Products

• Clarity PPM On Premise
• Clarity PPM SaaS

Issue/Introduction

Intermittently, users are receiving the popup message:

Unable to communicate to the PPM server. Please try again and if problem persists contact your system administrator.

Here is the error shown in the app-ca.log that is thrown when the user experiences the problem or communication disconnect in the browser:
ERROR 2019-10-29 10:47:57,791 [http-nio-80-exec-16] clarity.ui (clarity:session:odf.getObjectList) UI_MSG[:Tue Oct 29 10:47:28 EDT 2019:OnError called--Client Side Exception 
java.lang.Exception: VXMLRequest failed.  HTTP status code was: 0
at Unknown.Exception_0 (null:-1)
at Unknown.onResponseReceived (null:-1)
at Unknown.$fireOnResponseReceived (null:-1)
at Unknown.onReadyStateChange (null:-1)
at Unknown.anonymous (null:-1)
at Unknown.apply (null:-1)
at Unknown.entry0 (null:-1)
at Unknown.anonymous (null:-1)

Environment

Release: All Supported Release

Cause

When user gets the "Unable to communicate to the PPM server" popup and the error in the application log show HTTP status code was: 0:

• This occurs when trying to make or save certain application updates.
• This error could occur after making updates to properties.xml or Clarity CSA, specifically changes in the network configuration when more than one app server present in the environment.
• This error indicates there was a client/server disconnect but it's not clear what is blocking the communication.
• There is no clear reason or cause by associated with the error in the Clarity application logs.

Resolution

Steps below on how to troubleshoot this error/issue.

1. Does it happen in all browsers? (some browsers are more lenient regarding the client/server connection)
2. Are users on the same/different wifi/wired network/VPN/Working from Home?
3. Is antivirus installed on the client machine or Clarity servers (On-Premise customers only)
   • check for connections blocked at security tool (for On-Premise customers your internal security team will need to release any blocks on the Clarity servers)
4. Generate a browser trace/fiddler trace when the browser popup/error happens for user in real time to get more information on the blocked connection.
   1. Instructions:
      1. How to Generate a Browser Trace for Troubleshooting CA PPM Issues.
      2. Fiddler: https://www.telerik.com/fiddler
      3. Try another browser like Firefox or Chrome trace may provide more detailed information on the disconnect to troubleshoot the issue.
5. If the steps above do not reveal any client/server disconnect/environmental issues on your end, open a Clarity PPM support case and include:

• Note if the disconnect is intermittent in your environment; Intermittent issues tend to require deeper investigation in finding root cause.
• Attach to the case the fiddler/browser trace when the popup happens in the user browser, the Clarity PPM version, and any other details about the issue.|
  
  Obtain the app-access logs from the day the enduser reported the problem. Attach as a ZIP file for review.

Additional Information