Site Restoration

#38181 Session failed to start

Posted in ‘Site restoration’
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Environment Information

PHP version
CMS Type
CMS Version
Backup Tool Version
Akeeba Backup Professional 8.2
Kickstart version

Latest post by aglowintl on Thursday, 15 December 2022 16:06 CST


Trying to restore our site after a failed Joomla 3 - 4 upgrade. Now getting this message: Warning: session_start(): Failed to read session data: user (path: /tmp) in /home/xxx/libraries/joomla/session/handler/native.php on line 260

Any ideas for troubleshooting?

Akeeba Staff

Did you follow the documented instructions to delete your files before restoring?

I am referring to which states:

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.

This is especially important when you are moving between major versions (upwards or downwards). Joomla 3 and Joomla 4 have entirely different and incompatible files in the libraries directory, just to mention only one critical location. Mixing the two will result in a broken site.

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!


Thanks for the quick response, Nicholas. I've been using Akeeba Backup and Admin Tools for many years and very much appreciate the service you provide. Thank you!

I'll try the restore one more time, carefully following the instructions. I had removed all existing files and restored to a fresh database, so I don't think it was an issue of overwriting different versions. I probably just missed a step. Thanks for the recommendation.


Okay, ran the restore again with an older backup file. This time it worked. I think maybe the backup was incomplete, or some of the files were corrupt. At any rate, we're good now. Thanks again!

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