FAB 3000 can load and display multiple jobs simultaneously. When a layer has the "Hatched Pattern" on the Left - Indicates that Layer is not used in the Active Job.
Note: It is common not every job will use the exact same layers. This is only a visual effect to let you know which layers are not being used for the current job.
Note: The hatched patter (next to the layer name) only indicates that layer is not used in your current job.
How to eliminate the display of Unused Layer?
Best Solution: Syncrhonize Layer
Use the command "Synchronize Layers" (menu: Setup / Synchronize Layers...). This command will make sure the layers used on all Job(s) has the exact same name.
Note: Synchronize Layers is required for Panelization. For more information about setting up and using Synchronize Layers check out this link (or any panelization tutorials):
Fast Solution: Update Layer Display.
If you wish to only have FAB 3000 show the current layer(s) being used in job, than change the Layer Display to only show "Used Layers". Select menu item: View / Layer Display / Show Layers (Used Only)
Note: Once you have set this option there will be no hatched layers displayed in the layer table (only used layers). Some find it easier to work using this option.
Many users will ignore the unused layers until the final panelization steps when synchronized layers is required. It is really up to your preference.