Hi experts! I am a root beginner. I am working on a histogram tutorial. To solve the example called hbars.c, I type TBrowser b("cernstaff.C); to open the cernstaff.C file, and then "Error in : Trying to dereference null pointer or trying to call routine taking non-null arguments. Execution of your…

That’s a linux question. You can find the answer on the web for instance this one : How to Manage File and Folder Permissions in Linux - Linux.com