Offline payment + send to random user free event

Hi.
I have problem. I activate offline payment. 
But now system random send mail to remainder to pay for free event  
What could be the cause of this state of affairs?
Event is FREE.
EB ver. 4.1.0
Regards.

That's strange Marcin. Could you please submit a support ticket sending us super admin account of your site and tell me more details about this error (for example, how do you know that the system send remainder payment email, to what registrant...)

I will check to see what's wrong and guide you to correct it

Tuan

Thank you Tuan
I send Ticket [#121553]

Thanks Marcin. Asked you additional question, please reply via support ticket so that we can continue from there

Tuan