Critical error on this website

I can no longer export my WordPress blog posts. Every time I try I get a message:

There has been a critical error on this website. Please check your site admin email inbox for instructions. If you continue to have problems, please try the support forums.

I tried changing the export format from Docx to RTF, still same thing. My plug-in appears to be up to date.

Suggestions?

Sorry for the inconvenience. This plugin has been unlisted, as it uses the old API we no longer support. I asked the responsible team for their plans regarding this plugin.