I am new to CFD, trying to find my way around using Google and YouTube but I'm up against something I can't understand why. I understand what the error is - I think it's fairly self-explanatory, but not why I'm getting it.
I have attached 4 screenshots to show what I'm trying to flow through - so I can compare the results. I cloned the project and selected the other configurations, so unsure what's going wrong.
Thank you for any and all help,