Images & metadata not showing, style tab creates blank page

Hi,

I’ve been trying to create a popup-form for newsletter sign-up, but whenever I click on the “style” tab, the whole design disappears and a blank page is shown.

Also, when creating a newsletter E-Mail, no picture can be added. Neither the metadata in the library is shown nor is the image out into the email.

I did all the steps in troubleshooting mode to find issues with plugins or theme, but it seems to be a mailpoet issue. Any ideas what to do?

thanks for your help

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