Cannot convert access token to JSON

Last updated: November 2026

Condition

You may encounter the following error message when opening the Tunnel Setup Helper dialog in Katalon Studio: "com.kms.katalon.network.core.model.exception.NetworkErrorException: Cannot convert access token to JSON".

Solution

For users from the EU region or other regions outside the US region, log in or override authentication using your account subdomain.

Option 1

1. In the Log in to Katalon Studio dialog, select Advanced settings.
2. In the License server address, enter your subdomain URL in this format: https://{your_subdomain}.katalon.io.
3. Save and try again.

Option 2

1. Go to Project > Settings > Katalon TestOps Integration.
2. Expand Override authentication (legacy), then select Use different credentials for this project.
3. In Server URL, enter your account subdomain in this format: https://{your_subdomain}.katalon.io. Then enter your Email and Password.
4. Click Fetch Accounts to check that the override works, then choose your Account.
5. Click Apply and Close to save the settings.

To learn more, see Override authentication.