WooCommerce: "offer not found"

Hello!
I’m using your plugin in my woocommerce subscription extension and yesterday i switched from test to live mode. Everything is ok, the money is being transfered to Paymill, people get access to their content, but the problem is, that when they pay for theire membership, they are not redirected to thank you page – they get note “offer not found”

What should we do? I need to solve this asap.

Thank you!

https://www.ads-software.com/plugins/paymill/