Export problem

Hello,

I have an issue with Flamingo plugin. After I have several inbound messages, I want to export them but all I get after I click export button is a blank white page.

I have an image: https://lh3.googleusercontent.com/-Ullhcg8lGZ8/XH-TkhQxv_I/AAAAAAAABbM/Tm4by544OT8V7cY7-UcKfONuP6N49_92gCK8BGAs/s0/2019-03-06.png

And the URL looks like this: https://libertymarathon.uvt.ro/wp-admin/admin.php?page=flamingo_inbound&s=&_wpnonce=85e1328549&_wp_http_referer=%2Fwp-admin%2Fadmin.php%3Fpage%3Dflamingo_inbound&action=-1&m=0&channel_id=0&export=Export&paged=1&action2=-1

I don’t know what any informations I can give it to you to help me.

Thank you,
Sebastian.