root access failed or busybox was not found
A wild guess: You did not correctly install busybox.

BusyBox is not a simple application, it's a executable binary that should supposedly be located in /system/xbin. A correct installation of BusyBox includes copying the binary and creating symbolic links.

Judging by the version number you gave, you might probably installed something like "BusyBox installer" from Google Play or so. The (currently) newest BusyBox binary version is 1.26.1, so you may want to check again if BusyBox is installed correctly, not an app from GP.