Quick print issue – WP REST API

I am having trouble with Quick Print on a wordpress dot com blog. I have submitted a report from inside the wp admin > plugin > help page but haven’t heard back.

I have seen one other post with the issue but I don’t know if there is a clear resolution. The error says

“There seems to be an error initializing. Please verify you are using an up-to-date web browser.
Also check the WP REST API isn’t disabled by a security plugin. Feel free to contact Print My Blog support.”