Dominika

Nic podezřelého. To akorát Color Picker si chce "nahrát" pixely mimo okno aplikace a k tomu systém vyžaduje svolení uživatele. Viz System Settings → Privacy & Security → Screen Recording

Hello, 
I have An error occurred while exporting trouble too. (Publisher 2, macOS) It would be nice to know where the problem is and what to do about it. Thanks. 

Yes. However, it's not possible to open Affinity V2 files in Affinity V1.

Greetings all,
So, i had this exact same problem (Affinity Publisher+PDF export) and seemed to track down the problem and find a solution.
So, to brief it, the error message1 would come up whenever i tried to export this APub file (w/ 30+ pages, images of many sizes; text titles and subtitles, up to 5 different fonts, and interactive hyperlinked elements) into a PDF.
Initially i thought it was the size (i thought like: "really? ... can't be" - a i have a pretty reasonable rig). I tried almost all PDF export methods available in APub, and the only one that worked was the rasterize everything... which is a bit 'yucky' ...
So, as soon as i got a lil' time i went to track the problem down: I started exporting sections (pages 1-10, then 1-15, then 1-20, etc.) until i found which page was the problem, and then to make sure, i tried to export the section after it, and then that page alone. It was only one page.
So, in my case, it had nothing to do with Fonts; as i happened to find, there were 2 picture frames with very long (height wise) images inside; i rasterized those 2 picture frames and voilá, it worked. [update: It had to do with only one of the images, regular .JPG file, less than 1000 KB; see end of the post for JPEG detailed info]
It shouldn't happen, i know, and would be great if Serif/Affinity team could solve these almost random issues; but i hope it helps.
If your case is different, my 2 cents' advice is to try to track down what page(s) is the trouble-maker, and see what could be messing with the export.
Best Regards
SG
1 - "An error occurred while trying to export to: (...)"
PROBLEMATIC JPEG INFO:
Format                      : JPEG
Width                       : 844 pixels
Height                      : 1 804 pixels
Color space                 : YUV
Chroma subsampling          : 4:2:0
Bit depth                   : 8 bits
Compression mode            : Lossy
Stream size                 : 976 KiB (100%)
ColorSpace_ICC              : CMYK

I have no Mac, so I am not sure. The official documentation differs from your way:
 

Thank you so much! It works!:)