I have just being trying out the standalone payment module with payment-test.
I have enabled the Donation options in PayablesDemoPage.ss and PayableAdmin.php and I can see this listed on the Payments page of the website.
Clicking the [Make a donation] button brings up the correct form to submit a donation. However completing the form, selecting the currency from the dropdown and submitting renders this error:
Fatal error: Call to a member function setCurrency() on a non-object in /home/site/public_html/greatbig/sapphire/forms/MoneyField.php on line 104
Have I configured something incorrectly?
I have the following versions installed: