SCRWyatt

Thanks MEB.

Thank you all for your help. Here is a screenshot of my specs and I shall try Old Bruce's and MEB's suggestions. My mac has not had any issues running Affinity in the past.

Thanks Old Bruce, Yes they are RAW files in the Develop Persona. Are these different RAW engines within Affinity? Here is one of the files. P1160081.RW2

The following strange patterns have been appearing for me in developer since updating to 1.8.4. I use Mac OS 10.13.6 They come and go as I change settings, move the picture around or zoom in and out. My images are from a Lumix GH4. Please see attached screenshots.