Currently, when purchase on my site, i met this message "A valid amount is required".

I edited

x_amount = 1 -> OK

x_amount = 0.1 -> OK

x_amount = 0.09 -> show error

So, i want to know what's range(minimum and maximum) of x_amount. I spent 2 hours to search but have not any information about this.

Please help me,

Thanks,