Default translation engine: Failed to load engines

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

Problem:
The client is unable to perform translations due to errors related to the 'Default translation engine' failing to load and issues copying translation information to a new URL after migrating a site manually using an SQL file.

Solution:
1. Ensure the 'WPML String Translation' plugin is installed and enabled as it is necessary for using the Advanced Translation Editor and for translating strings from ACF, Yoast SEO, themes, or other plugins.
2. When encountering issues with fields not showing up for translation, verify that each field name is unique across various blocks or field groups. More information on this can be found here: https://wpml.org/documentation/related-projects/translate-sites-built-with-acf/
3. For errors related to URL mismatches after site migration, try editing the original content, saving it, and running the translation again. If the issue persists, it may be due to completing a job on one site URL and reviewing it on another, leading to URL errors.

If these steps do not resolve your issues or if the solution seems outdated or irrelevant to your case, we recommend opening a new support ticket. We also 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. For further assistance, please visit our support forum at https://wpml.org/forums/forum/english-support/.

This is the technical support forum for WPML - the multilingual WordPress plugin.

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Tagged: ATE

This topic contains 18 replies, has 1 voice.

Last updated by Andreas W. 1 month, 2 weeks ago.

Assisted by: Andreas W..

Author	Posts
July 1, 2025 at 6:39 pm #17189889
christopherH-36	Background of the issue: I am not able to do any kind of translation because my automatic translation services are bugging out It is producing this error "Default translation engine: Failed to load engines" Do you think this is because I created a copy of the site in my local? If you haven't noticed the site is in WP VIP. That means no migration plugins are allowed. What i did instead was generate an SQL file and imported it in my local environment's database and just updated the site urls. I went ahead and marked the site as a copy of the original site and not share the credits but I'm getting this error Error with copying translation information to new URL WPML was unable to copy your site's translations, translation memory, and glossary to this new URL. Please take a screenshot of this message and report this issue to WPML support. How do i fix this? and make sure this doesn't happen again in the future whenever I update my local environment with a fresh database from the production site. Symptoms: I am encountering errors: 1. Default translation engine: Failed to load engines 2. 'Error with copying translation information to new URL. WPML was unable to copy your site's translations, translation memory, and glossary to this new URL.' Questions: How do I fix the error with copying translation information to a new URL? How can I ensure this error won't happen again when downloading a fresh copy of the production site to my local environment?
July 2, 2025 at 7:40 am #17191158
Alejandro WPML Supporter since 02/2018 Languages: English (English ) Spanish (Español ) Italian (Italiano ) Timezone: Europe/Rome (GMT+02:00)	Hello, Could you please try again now? try to send the pages from WPML > Translation Management only for this test and let me know if it works (It should now). Regards.
July 2, 2025 at 3:36 pm #17194069
christopherH-36	Hi @Alejandro, it works now! Can you walk me through how I can prevent this problem again in the future? thank you very much.
July 2, 2025 at 7:02 pm #17194588
christopherH-36	Hi @Alejandro, I checked and the translation service is back online, but unfortunately, clicking the "Review" button in the translations queue is causing an issue. It's throwing the following error: app.js?ver=476000:1 Uncaught (in promise) TypeError: Failed to construct 'URL': Invalid URL at r (app.js?ver=476000:1:68893) at app.js?ver=476000:1:69073 at c (app.js?ver=476000:654:5830) at Generator._invoke (app.js?ver=476000:654:5583) at Generator.next (app.js?ver=476000:654:6189) at n (app.js?ver=476000:15:13709) at s (app.js?ver=476000:15:13920) at app.js?ver=476000:15:13979 at new Promise (<anonymous>) at app.js?ver=476000:15:13860 I browsed through existing tickets and noticed some suggest increasing the memory limit. I’ve already bumped it up to 512M. Do you think that’s sufficient, or could the issue be caused by something else?
July 3, 2025 at 6:59 am #17195454
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Hello, The error you are reporting can occur if you create a copy of your site while still having jobs in progress and reviews available that were not yet completed. This means that these jobs, including review, were created on a different site URL, and this is why you get an error now. You can solve this by editing the original content and saving it again, which should update the translation status and create a new translation job. After the new job is completed, the review should work. Please give this a try and let me know if further assistance is needed. Best regards Andreas
July 3, 2025 at 6:58 pm #17199102
christopherH-36	Hi, i tried editing the page and saving it but for some reason now when I view the translated page its returning a 404.
July 4, 2025 at 5:40 am #17199699
christopherH-36	Will providing access speed things up? Please let me know thank you!
July 4, 2025 at 6:41 am #17199894
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Hello, I would like to offer to take a closer look and request temporary access (wp-admin and FTP) to the website to investigate the issue further. You can find the required fields below the comments section when you log in to leave the next reply. The information you provide is private, meaning only you and I can see and access it. IMPORTANT Please be sure to back up your website and database before granting us access. If you can't see the "wp-admin / FTP" fields, your post and website credentials will be set to "PUBLIC." DO NOT publish the data unless you see the required wp-admin / FTP fields. The private reply form looks like this: hidden link Click "I still need assistance" the next time you reply. Video: hidden link Please note that we are required to request this information individually on each ticket. We are not permitted to access any credentials that were not specifically submitted on this ticket using the private response form. Best regards, Andreas
July 4, 2025 at 8:30 pm #17203069
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	The provided user account is not an admin account. Please adjust the user role inside the user profile and leave me a comment once you are done with this task.
July 4, 2025 at 10:47 pm #17203164
christopherH-36	Hi @andreas I can confirm it is an admin account. Due to the nature of the WP VIP you might not be seeing some functionalities simply because it is only a read-only environment.
July 5, 2025 at 4:55 am #17203392
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	Ok, I needed to enable 2FA for this account, now I can access the backend. I currently have no issue with opening the Advanced Translation Editor and translating the homepage, but to be able to translate everything, you still need to install the WPML String Translation Plugin and also activate WPML SEO. Regarding reviews: I am not able to see them on this account, as the reviews were possibly generated before this account existed. Could you please take those steps and try again to access the reviews? If you can not complete them for some reason, you could, in this case, mark the jobs that need a review at WPML > Translations and use the bulk option to accept the reviews. Also, if you want to translate your Custom Post Types, you will need to set the to "Translatable only show translated items" at WPML > Settings > Post Types Translation.
July 5, 2025 at 9:24 pm #17204302
christopherH-36	Yeah i kept on resetting and creating a new key in hopes all of these errors can be resolved but so far after something gets fixed another issue pops up again. I deleted the dutch version of the homepage and tried to run it through automatic translation again but the review button is producing an error and even marking it as approve in the bulk actions produces an error too.
July 5, 2025 at 9:26 pm #17204333
christopherH-36	Can the WPML String translation plugin be optional if I'm only planning to use ATE?
July 5, 2025 at 10:48 pm #17204357
Andreas W. WPML Supporter since 12/2018 Languages: English (English ) Spanish (Español ) German (Deutsch ) Timezone: America/Lima (GMT-05:00)	The plugin "WPML String Translation" is required to use the Advanced Translation Editor. You also need it for ACF and Yoast SEO or to translate strings coming from the theme or other plugins. Please install and enable the plugin, and then check if you still run into issues.
July 7, 2025 at 3:15 pm #17209840
christopherH-36	Everything appears to be working well now. However, I noticed that some of the translated pages aren't fully translated, some content is still showing in English. Could you take a look? I’ve confirmed that the relevant fields were set to translate in the ACF translation settings.