ATE Authentication Error: Unable to authenticate with the Translation Editor

This thread is resolved. Here is a description of the problem and solution.

Problem:
The client is experiencing an ATE Authentication Failure that blocks all translation work on their site. Despite resolving initial database issues, verifying server connections, and re-registering the site with a new key, the authentication error persists. The error occurs when attempting to start a translation job from the Translation Management dashboard, displaying an admin notice about authentication failure in multiple languages.
Solution:
We have escalated the issue for a server-side check by our technical team. The necessary steps include checking the status of the client's site key(s) and Translation ID in the WPML ATE cloud database, verifying that the subscription is correctly mapped to the translation service, and investigating any data mismatch or synchronization error between the site key and the pending translation jobs. We recommend the client to ensure that the translation engines are enabled in WPML Settings and to check the WPML API server and Toolset API server connections in the Installer Support section.

If this solution does not resolve your issue or seems irrelevant due to being outdated or not applicable to your case, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have installed the latest versions of themes and plugins. If the problem persists, please open a new support ticket at WPML support forum for further assistance.

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Tagged: ATE

This topic contains 15 replies, has 0 voices.

Last updated by saschaB-21 6 months ago.

Assisted by: Kor.

Author	Posts
October 14, 2025 at 11:52 am #17483495
Kor	Thanks for your reply. It's already in the queue for our 2nd Tier Support review and I will come back to you once I've feedback.
October 15, 2025 at 9:56 am #17486450
saschaB-21	Dear Kor, Thank you again for escalating this issue and for confirming the server-side check. We have successfully identified and resolved the cause of the persistent "Authentication Error" (ATE) on our side. The problem was a JavaScript conflict with a non-WPML plugin named "Add Admin CSS," which was running in our environment. This plugin's core files contained a global call to add_thickbox(), which is an outdated WordPress library. This old library conflicted with the modern JavaScript used by the WPML Advanced Translation Editor (ATE) to initiate its modal and communicate with the cloud service. Action Taken: Deactivating the "Add Admin CSS" plugin immediately resolved the ATE Authentication Error. All translation functions are now working correctly. We believe this conflict was likely triggered by a recent WPML ATE update introducing code that overlapped with the older library. Please close this ticket. Thank you for your support.