When trying to install Ninja Forms in my wordpress dashboard I get this error:
"Plugin could not be activated because it triggered a fatal error.
Fatal error: Call to undefined function wp_register_plugin_realpath() in /hermes/bosoraweb115/b466/ipg.dunkvolunteeringcom/wp-admin/plugins.php on line 150"
I am using iPage as a server and I have set the permissions of the wp-content to 777. I have tried installing through the dashboard, and following the instructions provided here (download, add contents to my plugins page and then activate).
I have read in other posts that one should replace the wp folders in some error cases, but I'm not sure if it applies to this error, and I don't want to erase anything I should not.
Does anyone have some ideas on what is happening and how do I fix it?
Thank you in advance.