Since layout was still running, I thought it would be smart to copy and paste my content into a new Layout document.
Then when I tried to save the new document Layout crashed (just quit).
I’m now not able to open any existing Layout files that I’ve created today.
I tried a restart of my PC (did this earlier today as well) but that didn’t solve it.
My previous versions of the Layout Document (which link to an older version of the Skp model) do open OK but when I update the SKP model, all the dimensions fly off into strange directions and there are odd graphical behaviours like text boxes becoming coloured.
I see a couple of issues with the LO file you uploaded. The viewports both use Last Saved View for the scene and both show as modified. I don’t think either of those problems would cause the save error but they will create problems for you as you work through the LO project. This includes the possibility of dimensions and label leaders pointing off page.
I started again and managed to create pages without any issues.
The only thing I changed was copying the Sketchup file from our server down to my Windows Desktop and creating a new Layout file next to it. Could this have caused such autosave issues?
Yes. It could have caused autosave problems if the server was accessible or the access time was to long. The general wisdom is to save files locally and sync to servers or cloud storage as needed.