I’ve been encountering this problem for a while now and I don’t recall when it started(but definitely after I had installed root on my desktop and used it without any problems for almost a year). The attached screenshot shows a window that pops out when I tried to save the histogram I drew from a root tree. I noticed that I could not tell what the folders are because the letters are so blurred! I built root 6.14 on my desktop running Ubuntu 16.04 following the instructions at https://root.cern.ch/building-root. I did not specify any build options though.
I did some search on google and did not find any topics related. I don’t even know if this is more of a ubuntu problem or of a root problem. I hope my descriptions are clear enough. Thanks a lot!
ROOT Version: 6.14
Compiler: g++ 4:5.3.1-1ubuntu1