Invisible annotations in PDF

[clared53587082]

I'm having the same viewing issue as in this thread from 2016: Comments invisible after latest upgrade - help?

When I open PDF files I have marked up, I can see all my changes in the comments list on the right-hand side, but the changes are invisible in the PDF itself. When I send these files to another person, they have the same issue. It only seems to happen in some files and not others, and it is not affected by zooming in/out.

I am running fully up-to-date Adobe Acrobat Reader DC 2019.008.20080.

I have tried opening the same file in an older version, Adobe Acrobat Reader DC 2019.008.20071, and I get the same issue.

I'm on a PC with Windows 10.

[clared53587082]

Update: The person I sent the file to said they fixed the issue by changing the view to 100%, but this doesn't work for me.

[clared53587082]

Update: The mark-ups came back. I have no idea why!

[Zac5DE3]

Same problem with you. My annotations are shown in the right column. And I can see them when I try to edit them. But they just become invisible as soon as I move my pointer away. It's so wierd. 

However, when I paste my existing annotations on other pdfs (which are visible and normal) to a new pdf, then right click to "set the format as default", the new annotations I create later do not have this problem.