[mezzanine-users] error occur when applying discount code when checking out or simply applying it before check out

error occur when click the APPLY button to apply the discount code when purchasing the product , having set the discount code correctly in admin account error info: django.utils.functional.__proxy__ object at 0x1033c4590 is not JSON serializable traceback info: -

Re: [mezzanine-users] error occur when applying discount code when checking out or simply applying it before check out

I also tried to quickly reproduce it, without any luck - it looks like it may be when the discount code is put into the session, but without the full traceback no one knows. I also can't stress the importance of providing a detailed description of the steps you've taken to cause the error. Please