I did a Design Rule Check on my unfinished PCB. For some reason the red lines (in my case showing NC) stay on the screen. I closed and reopened without effect. How can I solve that?
If you go to Tools, Design Rule Check, you should be able to click Delete Errors, then close the DRC dialog without clicking Check again. This will remove all existing DRC error markers in the design.
If I run the DRC on a PCB to "delete errors" the errors are removed immediately, run the DRC on a schematic and I have to refresh the screen to remove any errors.
Have a project with two or more schematics and run the DRC on the whole design. Each sheet gets its associated errors shown. To remove errors I have to do the "delete errors" on each individual schematic. The display errors applies to the project as a whole and the "delete errors" applies on a sheet by sheet basis.