Not sure…but try Preferences>Display Options> fallback graphics?
Also, go to help>about and copy paste your KiCad version information in your next post.
Ok i will post my version in next post
You have a graphics problem.
Making sure your graphics drivers are up to date. Download and install the most recent versions. That is probably the most common reason for the lines.
If all else fails, do as Bob recommends.
1 Like
1 Like
My problem is solved from bobz solution.
Thank you bobz
Thank you bobz my problem solved
It’s not a solution, it’s a workaround . . . fix your graphics drivers (if possible) for a solution. 
3 Likes