You are not allowed to write to root beginning with OS 10.11 El Capitan.

http://www.infoworld.com/article/2988096/mac-os-x/sorry-unix-fans-os-x-el-capitan-kills-root.html


BIAB 2026 Audiophile Mac
24Core/60CoreGPU M2 MacStudioUltra/8TB/192GB Sequoia/Tahoe, M1 & M5 MBAir, 2012 MBP
Digital Performer11, Logic, Finale27/Dorico/Encore/SmartScore/Notion/Overture