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Frontend crash with "Class 'JUri' not found" when disabling compatibility plugin (Edulif template)

Asked by frigi 1 month ago Last activity 1 month ago

I'm currently doing some pre-checks and planning for an upcoming upgrade from Joomla 5 to Joomla 6, following the official upgrade guide (https://docs.joomla.org/Joomla_5.4.x_to_6.x_Planning_and_Upgrade_Step_by_Step).

My server environment is fully ready with the correct PHP and database versions. Everything seems fine, but when I try to disable the backward compatibility plugin as part of my testing, the frontend of the site crashes completely with the following error:

Class "JUri" not found

For this site, I am using the Edulif template. It seems like the template is still using the old JUri class instead of updating to the new namespace (Joomla\CMS\Uri\Uri).

Has anyone encountered this issue with the Edulif template before? What is the best way to trace down which file or override is triggering this?

Any guidance or tips would be super appreciated. Thanks in advance for your help! 🙏

Accepted answer

Marked as the solution

Ziaul Kabir Staff

1 month ago

Hi,

Yes, during the upgrade preparation, you may experience errors or issues like the one you’re currently seeing when the Behaviour - Backward Compatibility plugin is disabled. This is expected if some parts of the current Joomla 5 site still depend on it.

You can continue with the Joomla 6 upgrade process. Once the upgrade to Joomla 6 is completed, you will no longer see the old Behaviour - Backward Compatibility plugin. Instead, you will see Behaviour - Backward Compatibility 6.

Please keep Behaviour - Backward Compatibility 6 enabled after the upgrade.

Thanks!

5 more replies

Ziaul Kabir Staff

1 month ago

Hello,

Thanks for reaching out to us. Could you please share temporary administrator access to your Joomla backend? You can provide the credentials securely in the hidden content section. Also, please take a full backup of your site before we make any changes.

Once I have access, I’ll investigate further and see what’s causing the issue. Let me know once you’ve shared the details!

Best regards,

frigi Asked this

1 month ago

Here is the information

Ziaul Kabir Staff

1 month ago

Hello,

For your information, you need to keep Behaviour – Backward Compatibility 6 enabled. If you keep it disable, it will through error.

Thanks!

frigi Asked this

1 month ago

If you leave only the Behaviour – Backward Compatibility 6 plugin enabled (and disable the one without the number), the error persists and you cannot proceed with the Joomla 6 upgrade.

So is it not possible to upgrade to Joomla 6 using the template Edulif?

Ziaul Kabir Staff

1 month ago

The process is to keep it disabled during the Joomla upgrade. Once the upgrade is complete, you can enable it again.

Thanks!

frigi Asked this

1 month ago

I currently have two Backward Compatibility plugins:

"Behaviour - Backward Compatibility"
"Behaviour - Backward Compatibility 6"

If I disable "Behaviour - Backward Compatibility" plugin the site crashes, independently if the "Behaviour - Backward Compatibility 6" is enabled or not.

Following the instructions on the documentation for the upgrade from Joomla 5.4.x to 6.x, I understand that the I should disable the old "Behaviour - Backward Compatibility" plugin and keep only the "Behaviour - Backward Compatibility 6" plugin.

As I understand, the procedure to check if the site is ready for the upgrade is to disable the "Behaviour - Backward Compatibility" plugin and verify that everything is working. If it is not working, then it means that I cannot proceed with the upgrade.
Is this correct?

Thanks!

In the docs