fatal error using WooCommerce Multilingual & Multicurrency

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

Problem:

The client experienced a fatal error when switching to English to create posts in WordPress, causing the site and dashboard to crash. This issue occurred when both WooCommerce Multilingual & Multicurrency and WooCommerce PayPal Checkout Gateway plugins were active.

Solution:

We identified that the issue was due to a compatibility problem between WooCommerce PayPal Checkout Gateway and the Classic Editor plugin. To resolve this, we recommended:

1. Keeping the Classic Editor plugin active.
2. Ensuring that WooCommerce PayPal Payments is updated and configured correctly, replacing the unsupported WooCommerce PayPal Checkout Gateway.
3. Upgrading to the latest version of WooCommerce Multilingual & Multicurrency, which includes improvements that might resolve the issue.
4. Testing the site after these adjustments to confirm if the fatal error is resolved.

If this solution does not apply to your case, or if it seems outdated, we highly recommend checking related known issues at https://wpml.org/known-issues/, verifying the version of the permanent fix, and confirming that you have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.

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

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Tagged: Bug, WCML

This topic contains 47 replies, has 0 voices.

Last updated by Bigul 2 weeks, 2 days ago.

Assisted by: Bigul.

Author	Posts
June 22, 2025 at 7:48 am #17156632
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, Thank you for the updates. I tested the issue in a minimal setup using the default theme and only the required plugins to check if the bug exists in a simple installation. Therefore, to help us identify the cause we have a request, please try the following: - Switch to the Virtue - Premium theme. - Then activate the other plugins in small batches (3–4 at a time) and check if the issue appears. This will help us narrow down which plugin might be causing the problem. -- Thanks! Bigul
June 23, 2025 at 1:36 am #17157846
Issei Miura	Hi Bigul, I have performed the checks that you have listed, working in the parent theme (Virtue Premium) and activating only Woocommerce and Woocommerce Multilingual and Multicurrency. By activating the plugins one by one, the plugin that produced the error when attempting to edit posts and portfolio items in English is the plugin, "WooCommerce PayPal Payments" When the WooCommerce PayPal Payments plugin is active together with Woocommerce Multilingual and Multicurrency, there error is present. With either of these two plugins deactivated, there is no error. I hope this helps. Let me know if you need further information from my end, thanks.
June 23, 2025 at 1:40 am #17157847
Issei Miura	Screenshot of the two conflicting plugins as described above
June 24, 2025 at 6:39 am #17163094
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, Thank you for the information. This looks like a compatibility issue. So we are continuing our analysis on this and will get back to you as soon as possible. Please wait. -- Thanks! Bigul
June 25, 2025 at 9:28 am #17167952
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, We have released a new version of WooCommerce Multilingual & Multicurrency that includes several improvements. After upgrading to the latest version, I conducted another round of testing. Post editing is now working correctly when both WooCommerce Multilingual and WooCommerce PayPal Payments are active. Please refer to this screencast for more details: hidden link Could you please recheck on your end and let us know if the issue persists? -- Thanks! Bigul
June 25, 2025 at 10:01 am #17168475
Issei Miura	Hi Bigul, Thanks for your update. I had a look now and I don't see the latest version, maybe it takes some time? I'll check again later, thanks.
June 25, 2025 at 1:31 pm #17169511
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, Thank you for the updates. I have already upgraded WooCommerce Multilingual to version 5.5.0 on your staging site. Please check if the issues still exist there. If you are planning to upgrade your live site, make sure to take a full backup first. Then, go to Plugins >> Add New >> Commercial and click the Check for updates button. This will refresh the installer cache and show the latest WPML update links. -- Thanks! Bigul
June 27, 2025 at 4:21 am #17175591
Issei Miura	Hi Bigul, Thanks for your update. I have tested the function and I still got the same error as before, however, when I activated the plugin "classic editor" that allows the option to choose block editor or classic editor, I could edit and open the posts using only 'classic editor' in English. Since I am always using classic editor to create and edit posts, there is not an issue for me because I don't use the block editor option. However, if the "classic editor" plugin is deactivated and there is only one option for editing posts, I cannot access them on the English side only. I have tried in both the staging site and main site both with the same result as above.
June 27, 2025 at 7:40 am #17176100
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, Thank you for the updates. Please keep the Classic Editor plugin active. I had temporarily deactivated it to test whether the fatal error occurs in a minimal setup. I hope you are following the same steps shown in the screencast I shared, as I was unable to reproduce the fatal error on my end. hidden link Therefore, please review the screencast and let us know your feedback. It would be very helpful if you could also share the exact steps to reproduce the issue on your side. -- Thanks! Bigul
June 28, 2025 at 2:01 am #17178876
Issei Miura	Hi Bigul, Thanks for your update. I watched your screencast, and I can do the same as you, I can edit new posts in Japanese without any problem. There was never any error coming from Japanese side. When I edit posts from English side, that is where the error comes. hidden link I can only edit posts in English if the "classic editor" plugin is activated and I use the option for 'classic editor' to open the English post. Thanks
June 28, 2025 at 2:01 am #17178877
Issei Miura	The screencapture file upload is temporary, so if you need me to upload and share it again, please let me know.
June 30, 2025 at 1:22 am #17181039
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, Thank you for the updates. I was able to reproduce the bug. It occurs when both the Classic Editor plugin and WooCommerce PayPal Payments are active at the same time. This appears to be a compatibility issue. Please note that the WooCommerce PayPal Checkout Gateway plugin is no longer supported. So, make sure you configure the WooCommerce PayPal Payments plugin instead. After that, activate WooCommerce Multilingual and check if the issue still occurs. You can refer to the attached images for more details. Please confirm the following: - Are you using the Classic Editor or the Block Editor to create and update posts? - Are you translating posts using the WPML Translation Editor, or are you doing it manually via the WordPress editor? -- Thanks! Bigul
June 30, 2025 at 1:58 am #17181137
Issei Miura	Hi Bigul, Thanks so much for checking into this and for helping find the source of this error. I will follow your advice about updating the Paypal Payments plugin. In the current setup, I can now create posts in English as long as I'm using the classic editor. To answer your questions: - I am only using classic editor to create and edit posts - Because the contents of our Japanese/English blog posts are often different, they are not always translated directly, with more or fewer text contents depending on the audience, so I am creating posts manually via the wordpress editor instead of using WPML translation editor. Thanks again for all your help. I think it will be totally resolved after the compatibility issue between classic editor and paypal gateway.
June 30, 2025 at 2:39 am #17181159
Bigul WPML Supporter since 01/2013 Languages: English (English ) Timezone: Europe/Vienna (GMT+02:00)	Hello, Thank you for the details. Please try the steps below — hopefully, they will help resolve the issue. Configure the WooCommerce PayPal Payments plugin the same way as the expired PayPal Checkout plugin. Then, activate WooCommerce Multilingual and check if the issue still occurs. I have one question. Does the fatal error only happen when editing English posts manually using the Block Editor? Please check this screencast for reference: hidden link We would like to confirm whether the issue is specific to the Block Editor and not affecting the Classic Editor when used with the PayPal gateway and WooCommerce Multilingual. If not, please share the exact steps to reproduce the bug (compatibility issue between Classic Editor and PayPal gateway). -- Thanks! Bigul
July 7, 2025 at 2:03 am #17205900
Issei Miura	Hi Bigul, After updates from the plugin Paypal Gateway to Paypal Payments, it seems the error has been resolved. There are sometimes an error message when attempting to use the block editor in English, but then after trying again, it works. Maybe about 1/5 of the times the block editor is opened, the error message appears. This is not a big issue for us because I don't use the block editor, I create posts using classic editor. It seems the issue was compatibility between the outdated Paypal Gateway and the block editor, but the error message contents kept including WPML multilingual and multicurrency, but now when the error appears, the WPML conflict doesnt appear. Thanks for your help and advice.