Unable to upload files from sidebar

Hello. I’m using most current version of folders plugin. I have a Woocommerce installed. I am able to upload files using main option from menu to upload files.

However when I’m using an upload function from Woocommerce Product view (add gallery) I get an error that upload was unsuccessful, please try again later. After a second my session is kicked out and I’m not logged in anymore.

This function does not work on production evironment, on localhost it works fine.

I checked file permissions and I think they are setup right.

Is there any way I can debug this error or check logs?

Here’s screenshot: https://i.imgur.com/niRqLTa.png