Thanks for reaching out! If you're still encountering the "Database engine timed out while serving the connection" error when trying to open an assignment in Sage 50 Student Edition, here are some steps that may help:

1. Move your SAI and SAJ files to a new folder on your C:\ drive.
2. Try opening the sample company to check if the issue persists.
3. If the sample company works fine, restore a backup of your assignment before the error started occurring.
4. Ensure you are using the latest version of Sage 50.
5. Check for Windows updates by going to Windows Start > Control Panel > Windows Updates > Check for Updates.
6. Verify your firewall settings to make sure they are configured correctly for Sage 50.
7. If none of the above steps work, you may need to perform an advanced reinstall of Sage 50.

For further details, you can refer to these articles:
 Database timeout troubleshooting
 Additional troubleshooting steps

Let us know if you still need help!

Warm regards,
Erzsi