How did you fix this? I am getting the exact same error when installing NextGen Plus 1.3.14:
Fatal error: Call to undefined method C_Component_Registry::is_module_loaded() in …/wp-content/plugins/nextgen-gallery-plus/ngg-plus.php on line 146
As a temporary fix, I am trying to downgrade to the previous plugin version but can’t find the repository of older versions of NextGen Plus. I only found the regular NextGen Gallery repository: https://www.ads-software.com/plugins/nextgen-gallery/download/ If anyone knows where I can find the Plus repository, that’d be great as well.
Thanks!