Exclamantion mark in bottom corner

I have run into a problem with layout that I can’t find the solution for. I import my scene in layout ( as I always do, for many many years but now the scene has an exclamation mark in the bottom corner and the scene doesn’t work. It seems to jump on if a select the box ‘preserve scale on resize’ but even when I put it off it doens’t work.

Does anybody know this problem ?

Click on ‘Render’

Ok, seems to work but it keeps happening thought. Do you know the reason as well ?

Check the ‘Auto’ if you want to refresh the render all the time you made a change.

Fantastic! Thank you very much!