Plugin could not be activated because it triggered a fatal error.

[NeilParticipant]

Hi, Was using the free Updraft plugin while building new site on my project server. Now want to go live and migrate the site into the permanent hosting site.

Source site is WP 4.6.1
Deactivated and deleted the free plugin.
Downloaded my Updraft Plus with Migrator 2.12.21 ZIP from my Updraft Plus account.
Uploaded by WP admin panel (with assistance from the ‘Upload Larger Plugins’ 1.4.1 plugin)
But when try to Activate get error:

‘Plugin could not be activated because it triggered a fatal error’

Fatal error: Call to undefined method PucFactory::addVersion() in /homepages/3/d133490343/htdocs/clickandbuilds/<sitenamehere>/wp-content/plugins/updraftplus/udaddons/plugin-updates/plugin-update-checker.php on line 1502

Also removed and manually FTP’d the ZIP file into the plugins folder but exactly the same response.

Any ideas please?

[udadminKeymaster]

Hi Neil,

This indicates that you’ve got another third-party (i.e. non-wordpress.org) plugin which uses the same library for integrating updates with the WP dashboard – this library: https://github.com/YahnisElsts/plugin-update-checker/ – but that it’s a really old version, and is causing a conflict. I’ve checked all released versions going back to 2013, and they are all compatible. So, it’s a plugin carrying a version from before then. If you can’t work out which it is (presumably it’s not been updated for a very long time), I’d suggest de-activating other plugins, and then retrying activating UpdraftPlus, and use a process of elimination.

David

[NeilParticipant]

Hi David,

I followed your suggestion and disabled all plugins except LMS Lifter (as it was difficult to install that on top of the theme and didn’t want to break anything). Updraft still not activate – same message. So migrated the site with a completely different tool. Now it is installed ok, I’ve reset the customer’s Updraft back to the free version and there are no problems.

I wonder if part of the issue may have been because the prototype build was created in a subdomain. Nevermind. The site is moved. Thanks anyway – I’ll keep this in mind for next time.

[Dee NutbourneModerator]

Hi,

I’m afraid that LifterLMS is the cause of the issue. We have had reports of this issue with that plugin before.

This is a known issue to the developers of LifterLMS. They have a post giving further details of the issue:
https://lifterlms.com/docs/plugin-update-checker-or-puc/

They recommend adding the following line to your wp-config.php file:
define( 'LLMS_LOAD_DEPRECATED', false );

This should resolve the conflict.

Best Wishes,
David N

[Author]

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