Ho notato che lo stesso identico errore si verificava se veniva stabilita una sessione di TeamViewer. Una ricerca su Internet mostra questa discussione .
Probabilmente, è un bug di incompatibilità per TeamViewer 11 con Sierra.
Problem 10:31:54.180203 +0100 kernel IOReturn IOAccelSurface2::surface_unlock_options(enum eLockType, uint32_t): surface is not locked.
Problem 10:31:54.259101 +0100 kernel IOReturn IOAccelSurface2::surface_unlock_options(enum eLockType, uint32_t): surface is not locked.
Problem 10:31:54.334998 +0100 kernel IOReturn IOAccelSurface2::surface_unlock_options(enum eLockType, uint32_t): surface is not locked.
Problem 10:31:54.411823 +0100 kernel IOReturn IOAccelSurface2::surface_unlock_options(enum eLockType, uint32_t): surface is not locked.
Problem 10:31:54.484102 +0100 kernel IOReturn IOAccelSurface2::surface_unlock_options(enum eLockType, uint32_t): surface is not locked.