Hi guys.
Lately i have seen this Dashed vertical line just to the right of the sidebar in the finder window (see image). I’ve searched the web, but since Im not native in english, is usually don’t get the best search results.
I am on a MacBook Pro (Retina, 13-inch, Mid 2014) running Mojave version 10.14.3 (18D109)
Seems to be a bug associated with transparency. If you turn off Reduce Transparency, it will go away. (According to the attached discussion.)
https://discussions.apple.com/thread/8554411?answerId=33991027022#33991027022
I have the same issue. Reduce transparency off did not fix it for me.
Wow! Does it remain after relaunching Finder?
Sometimes it is gone for a few minutes, but any window resizing will bring it back
Yes it does. Feels like I’ve tried most of the traditional solutions for common issues.
I have a bad feeling that it might be a early warning that something is going to stop working soon… Keeping those backups running in three different directions regularly now…
I’ve seen many reports on this. It is 99% sure a software issue (driver)
Maybe I should start thinking about a Nuke and Pave… Been in the back of my mind for a while now, just haven’t gotten around to it yet… Seems a bit drastic for such a little thing, but I think I would benefit from it in other ways as well.
I just noticed this on my rMBP 2015, and now I can’t unsee it, so thanks for bringing it to my attention! 
I was going to drag a screenshot box around it to post, but the artifacts go away as I drag the box. Mine are also sometimes multicolored.
Interesting little anomaly.
