Printing issue

It looks, at least initially, that upgrade to version 7 has solved the issue.

I can confirm that printing works as expected on emClient Pro 7.0.26687.0 WIN 10 Pro.
BUT,
Print Preview does not work at all:

I can watch the donut circling all day long! By the way: no problem at all with Thunderbird 45.3.0, not with print preview, neither with printing.

same here: Print-Preview not working.