Blank page when using AwoCoupon on checkout

Jesterday we installed AwoCoupon - everything works as expected.
But when we check out with a coupon we get a blank page after checkout.
The summary page is not displayed.

Site: http://www.peaknx.de/index.php?option=com_virtuemart&view=productdetails&virtuemart_product_id=22&virtuemart_category_id=9&Itemid=748&lang=de
Coupon: nxTESTcoupon

Without a Coupon everything is ok.

Do you have any suggestions for us?

Hello,

Can you go to global configuration and set error reporting to 'development' temporarily, then refresh the summary page again to see what the error is? And what is the url of the summary page you are referring to?

I set the error reporting to Development - no errors displayed.

The redirect URL is: http://www.peaknx.de/index.php?option=com_virtuemart&view=cart&Itemid=748&lang=de

Ok, thanks for reporting, I was able to reproduce it and have made an update. Please get the latest version, 2.3.3.1:
https://awodev.com/documentation/frequently-asked-questions#install-upgrade

Thank you - works great now!