TOPIC: Coupons are not working on my configuraition

Hello guys .
I just bought Quicksell component to my joomla then I installed and a removed then installed again . for some reason
And additionally i want to say i changed many permissions on my joomla . I tried Quicksell on my other web pages and coupons works correctly.
I think the problem stems from that i changed permissions.
Sure , i created coupon for my file and published it then when i'm trying it on page , apply button instantly returned "The coupon code seems wrong .. ."
what should i do right now ?
i copied , i gave repermissions , i removed , i clean installed but still not working.
which permissions should change ?
or what is the problem ?

you can check what i mean : My Web Page
coupon :PROMO20

help me please

Hi there,

Is the coupon added for that specific file that you have for sale? Can you email the screenshot as here it's downsized? Do you think you can provide some login info?

Thank you

I can provide all infos
Thank You

Thanks man I replied via email also.