The error "The plug-in execution failed because no Sandbox Worker processes are currently available. Please try again" indicates a problem with the Dynamics 365 Sandbox Worker processes, which are responsible for running your plugins in isolation. Even after restarting services and changing the isolation mode, the issue persists, suggesting a deeper problem.
Let's explore some additional troubleshooting steps to help you resolve this:
1. Verify Sandbox Worker Process Status:
- Event Viewer:
- Check the Windows Event Viewer on your Dynamics 365 server for any errors or warnings related to the Sandbox Worker processes.
- Look for events in the "Application" and "System" logs.
- Performance Monitor:
- Use Performance Monitor to check the CPU and memory usage of the Sandbox Worker processes.
- Look for any signs of resource exhaustion or abnormal behavior.
- Dynamics 365 Server Health:
- Ensure that your Dynamics 365 server is healthy and not experiencing any other performance issues.
2. Increase Sandbox Worker Process Resources:
- Server Resources:
- Ensure that your Dynamics 365 server has sufficient CPU and memory resources to run the Sandbox Worker processes.
- If your server is under heavy load, consider increasing its resources.
- Sandbox Worker Process Configuration:
- There are some configuration settings related to the Sandbox Worker processes that you can adjust.
- However, these settings are typically managed by Dynamics 365, and modifying them without proper guidance can lead to instability.
- Caution: Only make changes to these settings if you have a thorough understanding of their implications.
3. Check Plugin Code and Dependencies:
- Plugin Code:
- Review your plugin code for any potential errors or resource-intensive operations.
- Ensure that your plugin is properly handling exceptions and releasing resources.
- Dependencies:
- Check if your plugin relies on any external dependencies (e.g., third-party libraries, web services).
- Ensure that these dependencies are available and functioning correctly.
- Infinite Loops:
- Check the code for potential infinite loops, which can consume all available resources.
4. Check Asynchronous Job Queue:
- System Jobs:
- Go to Settings > System Jobs in Dynamics 365.
- Check for any failed or stuck asynchronous jobs.
- These jobs can sometimes interfere with the Sandbox Worker processes.
- Asynchronous Service:
- Although you restarted the asynchronous service, it's worth checking its logs for any errors.
5. Re-Register Plugin (Different Context):
- User Context:
- Try registering the plugin under a different user context (e.g., a system administrator).
- Impersonation:
- Ensure that your plugin is not using impersonation in a way that causes problems.
6. Database Connectivity:
- Database Connectivity:
- Verify that your Dynamics 365 server has a stable connection to the SQL Server database.
- Check the SQL Server logs for any errors.
7. Dynamics 365 Updates and Patches:
- Updates:
- Ensure that your Dynamics 365 server is running the latest updates and patches.
- Microsoft might have released fixes for issues related to the Sandbox Worker processes.
8. Reinstall Dynamics 365 (Last Resort):
- Reinstallation:
- If all other troubleshooting steps fail, consider reinstalling Dynamics 365.
- This is a last resort and should only be done with proper planning and backups.
9. Contact Microsoft Support (Escalate Further):
- Escalate:
- Since your initial support ticket didn't yield a response, escalate it further.
- Provide them with detailed information about the error and the troubleshooting steps you've taken.
- Mention that you've already restarted services and changed the isolation mode.
- Collect Logs:
- If possible, collect relevant logs from the Event Viewer and Dynamics 365 server.
- This will help Microsoft Support diagnose the issue.
Key Recommendations:
- Focus on the Event Viewer: The Event Viewer is your most valuable tool for diagnosing Sandbox Worker process issues.
- Check for resource exhaustion: Ensure that your server has sufficient resources.
- Escalate your support ticket: Don't hesitate to escalate your support ticket if you're not getting a response.
By following these steps, you should be able to identify the root cause of the problem and resolve the Sandbox Worker process error.
