Sorry for the delay - I found your message in my Spam folder for some reason!
First, some initial questions so we can help troubleshoot this:
Have you followed our recommended installation instructions for your version (e.g. Ubuntu 18.04, PHP 7.2, ES 5.6, Nginx, etc)? If no
What is the default installation culture used in your application? (es or en, etc)
Have you upgraded recently? If yes, did you remember to follow all steps in our upgrading documentation
, including dropping and recreating the database prior to loading your data?
Have you tried any of the common AtoM maintenance tasks to see if it helps resolve the issue? (clearing the application cache, rebuilding the nested set, restarting PHP-FPM, etc)
Were you attempting to perform this with an administrator account, or a different user/group account? Have you customized the permissions much in your AtoM installation (for example, changing the default permissions of some of the groups like editors, administrators, contributors, etc; adding custom per-user permissions; creating custom groups, etc)?
Does this error occur as soon as you try to navigate to the page, or when you try to save a new function?
If when trying to save: were you trying to add a new function and relate that function to something (a description, another function, etc) using the Relationships section of the edit form at the same time?
Is there any other information about your installation environment, or the steps leading up to the error, that you think it would help us to know?
Thanks in advance! Hopefully with a bit more information we can provide further suggestions.