I just upgrade my Apex install to 20.2 a few days ago and was trying out the new native Excel and PDF printing. The native Excel printing worked great. I love how well the results are formatted. I've been using open-source code to get XLSX format and this works much better.
Then I tried to download my Interactive report as a PDF. I am getting 503 -- Service unavailable and a message "Producing PDF resources is no longer supported". I understand why I'd get this before 20.2 because FOR was desupported. However, since printing in PDF from IRs is supposed to be a new feature of 20.2 I don't know why I'm getting it.
I created a new app in 20.2 and an IR in there. Printing to PDF worked fine.
I created a new page in my pre-20.2 app and created an IR there. I got the 503 error.
The 'Compatibility Mode' of my app is set to 19.2/ 20.1 / 20.2. Is there some other setting I have to flip to enable PDF printing in 20.2 for apps created in earlier releases?