core 2.0.05, i have run this file before and it showed all layers in older version preview , but only shows as black mass now unless i zoom way in , is theer a setting they may not be active that im missing , i have done a test run and it engraves at the diffrent power setting as should , just not showing clearly in preview
What you show here is what I have always seen. If you reduce the LPI to a smaller value, you will see it look more grey.
You can always install an older version over the current one to verify your suspicions. If you get something different in Preview, please share the image so we can all see it. There is no need to uninstall Lightburn first. I have no other software where you can do this.
1 Like
Please post this project file so we can take a closer look. 
