There is nothing much complicated here in this add-on.
The admin should have a personal account and the sellers should have a merchant account. Then the admin has to contact PayPal Support to get the details for Dokan. After they provide you the details, follow this doc to set up your PayPal Adaptive add-on for dokan http://docs.wedevs.com/category/add-ons/dokan-add-ons/paypal-adaptive-payments/
There is all the steps described in details in the docs.
Only two things can make it not to work:
- Incorrect or incomplete Information in the settings.
- The seller have not set his mail address.
Check the settings
Login to wp-admin and navigate to WooCommerce -> Settings -> Checkout -> PayPal Adaptive. Check if the payment method is enabled and all the data is present where is needed. If you believe all the data there is correct, then move next. Otherwise you can cross check the details to be sure.
Check the seller mail
Most of the time the error in checkout happens because of seller has not entered his PayPal mail address. While the customer checks out with a sellers product to PayPal, they get the mail address to send the money. So if the seller has not entered any mail address at all or the mail address is not correct, then some error might pop out as PayPal is not getting any correct mail.
These are the possible problems and solutions for PayPal Adaptive payment add-on for Dokan.