can't insert wordpress posts

Hi there,

I can’t insert the WordPress posts block. As I chose posts that I want to want to insert from the wordpress box, it just showing “inserting the post” message bottom of the box page, and does not insert the posts.

For your information, I’ve been using Mailpoet for more than a year. During that time, it has never occurred any problem. In addition, I did not install other plugins from the time that I sent e-mails to my client successfully last time.

Thank you in advance,

Jae K.

https://www.ads-software.com/plugins/wysija-newsletters/