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Site Restoration

#39051 Class "Joomla\Plugin\Content\Fields\Extension\Fields" not found

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Environment Information

PHP version
8.1.16
CMS Type
Joomla!
CMS Version
4.3.1
Backup Tool Version
9.6.1
Kickstart version
9.1

Latest post by nicholas on Thursday, 01 June 2023 09:29 CDT

vincentsimon

Hello,

 

After restoring the wesite, I occurred the following error message 

Class "Joomla\Plugin\Content\Fields\Extension\Fields" not found

and I cant access to administrator web page : 

Class "Joomla\Plugin\Authentication\Joomla\Extension\Joomla" not found

 

Regards

System Task
system
The ticket information has been edited by Vincent SIMON (vincentsimon).

System Task
system
The ticket information has been edited by Vincent SIMON (vincentsimon).

nicholas
Akeeba Staff
Manager

You restored a Joomla 4 site on top of a Joomla 3 site. Please read the relevant documentation bit:

Do not try to overwrite one Joomla! version family with a different one. Overwriting a major version with another (e.g. restoring a backup taken on Joomla! 3.7 on top of a site running Joomla! 2.5 or vice versa) or between different minor versions (e.g. restoring a backup taken on Joomla! 3.7 on top of a site running Joomla! 3.6 or vice versa) will NOT work. Joomla! moves files around between minor and major versions. Since the backup does not delete files not present in the backup archive this will end up with Joomla! being "confused" and malfunctioning. In these cases you should delete the existing files and folders (except, perhaps, user generated content) before restoring the backup. You can safely restore a sub-minor (path-level) version on top of another. For example, you can safely restore a Joomla! 3.7.5 site on top of a Joomla! 3.7.3 site or vice versa.

https://www.akeeba.com/documentation/akeeba-backup-joomla/restoring-backups.html#general-guidelines

While this was not always very important on Joomla 3.x versions (especially on Joomla 3.9 and 3.10), it is very important when the newer site is on Joomla 4.0 or later. There is a massive number of internal changes in Joomla between versions 3.x and 4.x, and there are a quite a few important ones even throughout the Joomla 4.x version family.

Nicholas K. Dionysopoulos

Lead Developer and Director

🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!

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