Symptoms
- An “unknown communication error” appears when you attempt to save changes after a period of inactivity
- The error provides no clear indication that a session timeout caused the failure
- Save operations fail silently or with a generic network error
- Starting with version 24.8.6, a specific timeout message with a Log in button appears instead
Root Cause
Concurrent Polarion licenses enforce a session timeout (typically 30 minutes of inactivity). When your session expires while working in Risksheet, the server rejects save requests because the authenticated session no longer exists.
Resolution for Version 24.8.6 and Later
Step 1. When the session timeout message appears, click the Log in button shown in the error dialog. Step 2. A new browser tab opens to the Polarion login page. Enter your credentials to re-authenticate. Step 3. Close the login tab and return to your Risksheet tab. Step 4. Retry the save operation. Your unsaved changes remain in the grid and should save successfully with the restored session.Resolution for Earlier Versions
If you are on a version prior to 24.8.6, the error appears as a generic “unknown communication error” without a login link. Step 1. Open a new browser tab manually. Step 2. Navigate to your Polarion instance URL and log in. Step 3. Return to the Risksheet tab. Step 4. Retry the save operation.Prevent Session Timeouts
Risksheet includes a built-in keep-alive mechanism that sends periodic heartbeat requests to the/api/keepalive endpoint on the Polarion server. This endpoint returns HTTP 200 to maintain your session and works automatically in the background.
If you still experience timeouts despite the keep-alive:
| Check | What to Verify |
|---|---|
| Server timeout configuration | Ask your administrator whether the concurrent license timeout (default: 30 min) can be increased |
| Browser background requests | Some browser extensions or security policies block the keep-alive heartbeat |
| Tab throttling | Modern browsers throttle background tabs, preventing timely heartbeat delivery |
| Network stability | Corporate proxies may drop idle connections before the keep-alive interval |
Upgrade Recommendation
If you frequently encounter session timeout errors with the generic “unknown communication error” message, upgrade to Risksheet version 24.8.6 or later. The improved error handling provides:- A clear message explaining the session timeout cause
- A one-click Log in button to re-authenticate
- Preservation of unsaved changes during re-authentication
Verification
After re-authenticating, return to your Risksheet tab and click save. You should now see the save operation complete successfully without timeout errors, and all your changes persisted to Polarion.See Also
- Save Operation Failures — other save-related errors
- Access Denied Errors — permission issues
- Slow Page Loading — performance and network issues
- Browser-Specific Issues — tab throttling and browser behavior
Sources
Sources