Symptom: Trying to use tutorial to create my own Joomla Registration page. Upon submitting the form, debug showed no errors, but no records were added to the database users table. After solving the problem, I discovered that a debug that is successful actually shows the data added to the table - if you're not seeing that - no point in flipping back through admin panels to check.
Solution: discovered the Green vs. Red bars... vs. green checks and x's. For others that may stumble on this post: After clicking on the form name in the Forms Manager and clicking on the Plugins tab... clicking on the "Joomla Registration" plugin green arrow turns that row to green and leaves a red X. Intuitively (at least to me), green checks meant to me that all of those plugins were running and good to go. In actuality, green checks must be clicked to be activated. I have used an extension called QuickFAQ in the past that uses the same checks and X's in reverse function.
Back to my project,
coffeej