SwissEngineer

So Patrick Gilmour found the solution: Restart the Mac. (I had also re-downloaded the App from the Affinity Website and deleted its preferences.) Able to open the file again, therefore I have deleted the file.

Thank you so much, yes that solved the issue. So in relation to the original post I did delete the App, deleted preferences of Publisher, re-downloaded it from the Affinity website, and restarted the Mac. Voilà. Thank you for suggesting the solution, Patrick Gilmour 🙂

You are right. As I found out all is good, ie I have the directly bought version, and after a restart and such it starts up and opens the file.

Ok tried to delete ~/Library/com.seriflabs.affinitypublisher, and ~/Library/Preferences/com.seriflabs.affinitypublisher.plist. Started Publisher. It did start up, but remembered two files I had worked with in Recent files. Tried the older one, not the one I had uploaded here. And spinning beach ball again. Found out I had bought this one (in contrast to Designer and Photo) directly on the website with an older email. So my posts are about the directly bought version.

This is what I do: Open the Affinity Publisher App, and I guess it is loading the file but I do not know. Do you have a trick so it does not load any previous file?

Yes, macOS 10.15.6 Catalina, MacBook Pro (Retina, Mid 2012) 8 GB RAM, Affinity Publisher 1.8.6 (directly from Affinity downloaded version), opening a book of 300 pages, text mostly, few pictures, had saved that file from within Affinity Publisher. When I open Affinity Publisher it opens, only when I load a file like the one below or create a new file from presets it stalls with a spinning beach ball. I need this book urgently and already have worked hours on the text which now is lost/locked. Have tried redownload and deleting preferences to no avail. Patrick Gilmour suggested restarting the Mac and indeed that did solve the issue.