Rendering issues in Dimension

Renders are just messing up on my system, it's really frustrating, I can't find any solutions online.

It doesn't give me the option to specify GPU or CPU anymore so i think that could be part of the reasons. But the rendering either stops at 50%, or doesn't event start at all. The last couple of attempts all led to the software crashing.

I literally just started using dimension and at the start this was never an issue