"<local6>" likely refers to a local variable or parameter in the connector code that is expected to hold the private key object, but it is null, causing the NullPointerException.
To resolve this issue, these are few steps which might help you in resolving the issue:
1) Verify that you have correctly configured the private key file (.p8 or .pem) in the Snowflake connector settings. Double-check the file path, format (PKCS#8 or PKCS#1), and permissions.
2)Ensure that the private key file itself is not corrupted or modified.
3)Check if you are using the latest version of the Mendix Snowflake REST SQL Connector from the Mendix Marketplace. Outdated versions may have bugs or compatibility issues.
For further deep details on troubleshooting check out,