The extra ResizeImageOnUpload is very old and this path only works on MODX 2.x.
If you really need to use this extra with MODX 3, then take a look at this thread:
Hello everyone,
Has anyone of you got the plugin “Resize Image On Upload” to work under Modx 3?
I changed the “require_once” path from “/core/model/phpthumb/phpthumb.class.php” to “/core/vendor/james-heinrich/phpthumb/phpthumb.class.php”. This was displayed as an error in the error log. But after the change I have no more errors in the logs but it still doesn’t work properly.
Has anyone had any experience with this?
Alternative question: How do you do that for your customers/authors who are …