Ensure you are using the correct tunnel app for which the file was created.
If it is not a config file, it may be an old, obsolete image thumbnail format. Download Telenor File tnl
The configuration may be expired (commonly happens within a few days) or the server is overloaded. Ensure you are using the correct tunnel app
Official Telenor settings are typically delivered via SMS or manual APN configuration, not through custom .tnl files. How to Use .tnl Files for Telenor (General Guide) Official Telenor settings are typically delivered via SMS
Obtain the Telenor-specific .tnl configuration file from a reliable forum or Telegram group. Import the File: Open the Tunnel App.
Configure manually by going to Settings > Mobile Networks > Access Point Names and entering: Name: Telenor Internet APN: internet Username: Telenor Password: Telenor Troubleshooting .tnl Files
This will help me give you more tailored, safer instructions. Mobilink and Telenor Internet Settings | PDF - Scribd