We are using Outlook email. We are using the tab browser technique. Starting at the Outlook home page, there are several panes. When you open an email with a PDF, then click on the attachment, it opens in like a pop-up. At the top, there are two buttons, a download and print. When you click on the print the new window event fires, and we create a second tap. The window is blank. I have a shortcut that will copy that tab's URL. If I copy and paste it into a Chrome browser, you can see the document with Chrome looking print UI. I can send you the link. I am not sure how long it is available, and/or because of cookies, you may not be able to access it. I am somewhat struggling to describe it, I was hoping trying to print a Google document might be some sort of clue. Looking at a Devtool on Chrome, I see a lot of type script, initator *.js, with status of 200.

Here is the link, I cut out some where the ellipses are (...)
https://attachments.office.net/mail/pdfprint.html?id=AAMkADU4NWM1NTc1LT (...) ANARY=X-OWA-CANARY_cookie_is_null_or_empty&owa=outlook.office.com&scriptVer=20250502003.07&clientId=xxxxxxxxxxxxxxxxx&routingKey=Stxxx%2540braums.com&animation=true

Let me add another note... I just emailed it to my personal email, which gets forwarded to Gmail, so using the Gmail browser, when I clicked on the printer icon, it showed in a new tab and is able to be printed.
I wonder what Outlook is doing differently?

Hi,

Sorry about the delay. We were able to find out the root of the issue. This will be fixed in our next build. We will reply here again as soon as the new build is available.

Thanks!

Loaded it down, and it looks to have fixed that issue. It's a little bit tricky to start testing in stores, I have to make sure to compile any programs that use the EO DLLs. Besides, it is Friday. :-) Hope to get it in the stores sometime next week and will let you know if there are any other things we find.