I contacted Nvidia about the wall and door problems I was having and about the flashing screen issues.
They asked me to submit a number of files and asked for quite a few questions to be answered.

They came back after examining the evidence and said it is application specific so it must be a dressed by the applications developers.

If any developers read this, this is the really strange thing that happened and it might give you some insight into what is going wrong with Nvidia as it is related to Sharks preferences folder.

As I am running the desktop with just an Nvidia card and the laptop with both Intel and Nvidia I have the ability to test a couple of things.
After the error on the desktop I thought I would see if the laptop was doing it, but because of so many issues with flashing screens I run Shark on the Intel chip on the laptop.

I opened the program and used the exact same steps, a 10 metre wall and a 0.76 metre door, no problem; it worked fine on the Intel chip.

I then went into the Nvidia control panel and selected Shark to use the Nvidia card and tried the wall again, when I did this I received the same error as I did on the desktop so that told me it was Nvidia related.

I then went back into the Nvidia control panel and removed Shark from the list so it was running back on the Intel chip, restarted the program, tried the wall again and received the same error on the Intel chip which did not happen before I used the Nvidia card!

I figured it might need a system restart so I did that but when I tried the wall again on the Intel chip it gave the same error. I then uninstalled Shark, cleaned out the registry, reinstalled Shark and tried it again, the same error came up.

At this point I was stumped, how could it work before using the Nvidia card and then not work after the Nvidia card was disabled?

After thinking about it I realised that the only thing left when the program is uninstalled is the preferences folder. I dragged the preferences folder out of the Shark users folder and started Shark as if it were a fresh install and the wall/door function worked fine.

I then returned the preferences folder to its main folder, started Shark and tried the wall again and got the error, so it has something to do with the files in the preferences folder!

This has confused me big time, I set-up Shark on the laptop with new preferences and the wall/door tool works fine but if I used the Nvidia card again the same thing would happen.

I have proved this beyond a shadow of a doubt this morning, if small pallet icons are used or the pallets are torn off or if the Inspector/Snaps/Concept Explorer are kept open the program will crash or the door tool will mot recognise there is enough space for a door.
I had been working with all my pallets closed and the program was responding well, as soon as I opened up my Inspector/Snaps/Concept Explorer pallets the program crashed as is displayed in the screenshot.

So if any of you are having crashes even when not using the architectural tools, delete your preferences file.
When you set up your new preferences do not use small pallet icons, tear off pallets or leave the Inspector/Snaps/Concept Explorer open and see if the program acts differently.

That might indicate that it is a 32 bit or Windows only error , are any 32 bit users out there willing to test it? Rokoko can you try tearing off a few pallets, closing the program and trying again please?
I am also starting to think that these pallets are causing the flashing screens and disappearing images some Windows users have been experiencing, if I have time later I will test that theory.

Thanks, it must be a Windows only and/or a 32 bit problem, my workaround is to keep a copy of the SFXPrefs.ini file that works for architectural tools and replace the one that doesn’t work with it. If I tear off pallets another strange thing is that one moves back to the top left corner from time to time, only the one pallet does it!