Service Unavailable

I did not do anything except change one of my PDF products to Agreement Required.
Then I stated getting an error when checking out "Service Unevaluable"
Here is the error message below.
What do I need to do to fixe this?
Argument 1 passed to fn_get_edp_notification_rules() must be of the type array, boolean given, called in /home/whiteblazepages/public_html/store/app/functions/fn.cart.php on line 2636
Error at
app/functions/fn.cart.php, line: 10856
File: app/functions/fn.cart.php
Line: 2636
Function: fn_get_edp_notification_rules
File: app/addons/paypal/payments/paypal.php
Line: 170
Function: fn_change_order_status
File: app/functions/fn.cart.php
Line: 1650
Function: include
File: app/functions/fn.cart.php
Line: 9760
Function: fn_start_payment
File: app/controllers/frontend/checkout.php
Line: 378
Function: fn_checkout_place_order
File: app/functions/fn.control.php
Line: 679
Function: include
File: app/functions/fn.control.php
Line: 430
Function: fn_run_controller
File: index.php
Line: 25
Function: fn_dispatch

It only does this for one of my products.

I figured out what the problem was.

I had the my "files for sell" Activation mode set to "Immediately" .

When I changed it to "After full payment", it started working correctly.

The question is, what won't it work if I set it to "Immediately"?

Try to make a post with issue details in the bug tracker