DeleriousX on "[Plugin: WP-Filebase Download Manager] "Forbidden" message when hitting "add file""

I click the Select Files button, pick my file and I get the file uploaded message. But when I click "add file" I get the forbidden message.

Anyone know why?
I know it was working in the past, just have no clue what have changed.

WP 4.5.2
Filebase 3.4.4

https://wordpress.org/plugins/wp-filebase/