Keep adding Custom Fields but nothing is updated despite getting confirmation of "Settings Upda

That was then,
Now, I am getting this when opening each tab of the plugin:

Rendering of admin template /home/campusfo/public_html/bu/wp-content/plugins/custompress/ui-admin/navigation.php failed

Rendering of admin template /home/campusfo/public_html/bu/wp-content/plugins/custompress/ui-admin/post-types.php failed

Rendering of admin template /home/campusfo/public_html/bu/wp-content/plugins/custompress/ui-admin/navigation.php failed

Rendering of admin template /home/campusfo/public_html/bu/wp-content/plugins/custompress/ui-admin/custom-fields.php failed

What to do?