# Why am I seeing 'Internal Server Error' when discovering Layer 2 map?

If you have installed OpManager in a Linux box running in console mode, you may encounter this issue.

The issue is because the **X11 windows server** display variable might not be set to the correct value. In such case, the Layer 2 map will be discovered internally.

However, OpManager will face problems in rendering it in the browser.

To resolve this, execute the below command with super user privilege:

```bash
export DISPLAY=:0
```

## Related Products

- [Network Monitoring](https://www.manageengine.com/network-monitoring/?relPrd)
- [Bandwidth Monitoring & Traffic Analysis](https://www.manageengine.com/products/netflow/?relPrd)
- [Network Configuration Management](https://www.manageengine.com/network-configuration-manager/?relPrd)
- [Switch Port & IP Address Management](https://www.manageengine.com/products/oputils/?relPrd)
- [Firewall Management](https://www.manageengine.com/products/firewall/?relPrd)
- [Network Monitoring Software for MSPs](https://www.manageengine.com/network-monitoring-msp/?relPrd)
- [IT Operations Management](https://www.manageengine.com/it-operations-management/)
- [Application Performance Monitoring](https://www.manageengine.com/products/applications_manager/?relPrd)