[fziegler]

I have to admit, I haven't yet understood how exactly to proceed for making annotations within larger PDFs.

A first annotation (e.g. inserting a coloured rectangle) isn't a problem. But if I try to add a second annotation (= not a second element, but a second saving to add new annotations to existing ones), the app crashes every time: I can add those annotations, but every time I hit the (x) button on the top left, it's off and away. It's reproduceable. I use the feature to save annotations directly within the PDF.