I use Linux Mint reader and some of the pages are cut, others layered with text underneath. The screen shots explain better than me!
Apparently the translation from HTML (or whatever the smart kids use these days) to PDF cannot handle all the layouts. In particular, those fancy animated diagrams die in a PDF document.
I tried using the PDF document for a while, but keeping a browser tab aimed at the doc worked out better for me.
I can download the PDF through the browser to open directly in a PDF reader. The result is the same. I use Firefox, perhaps there is an incompatibility issue somewhere. I normally have no problems with PDFs normally. Going through the Help in Lightburn gives me the option of the on line version which for me doesn’t help much or version 1.6 or older. Another browser possibly to see if that helps. The documentation is not helpful when you can’t read it all. Perhaps somebody can suggest a work round.
The problem is with whatever does the conversion from the online doc to the PDF, not whatever you’re using to read it; the file works equally poorly in three different PDF readers I tried here.
The definitive source:
There’s a dropdown on the menu bar at the top to select the version:
Keep that tab open and the Search feature will get you where you want to go.