Black screen with cursor after logging out of guest account on High Sierra
How I solved this issue on Mac OS 10.13 High Sierra:


Boot into Recovery Mode (Command-R)
Open Terminal, disable SIP (csrutil disable), restart
Login to Guest, logout (it should not hang on a black screen now)
Boot into Recovery Mode (Command-R)
Open Terminal, enable SIP (csrutil enable), restart
Login to Guest, logout (it still works!)