Unusual black line beside line numbers on the left

[Masrafi]

I have recently switched from windows 10 to Ubuntu (Linux). When I installed codeblocks on ubuntu a strange black line with white boxes in it appeared beside the line numbers on the editor. When I was on windows it wasn't there.
How can I remove it... :/

[BlueHazzard]

Version of codeblocks?
Source of installation?
Version of ubuntu?

Some screenshot?