All parameters are in place and everything works fine when pointing the live paypal site. Unfortunately I'm getting "Your payment can't be processed. Please contact the merchant directly." when pointing the sandbox. Why is that?
I created test user for seller and buyer as stated in the official guides.
I'm referring to this guide: https://cms.paypal.com/cms_content/GB/en_GB/files/developer/HostedSolution.pdf
I'm using "https://securepayments.sandbox.paypal.com/acquiringweb" for sandbox and "https://securepayments.paypal.com/acquiringweb" for live
Ideas?
Perhaps check out this PDF: https://www.paypalobjects.com/webstatic/en_GB/developer/docs/pdf/hostedsolution_uk.pdf
You might also want to check out the MTS Knowledge Base. Here's a post from there:
https://ppmts.custhelp.com/app/answers/detail/a_id/738/kw/hosted%20solution