I assume you are using a Linux distro on R6415. This happens when the Linux kernel-perf doesn't support access to PMC MSRs. On Linux, uProf uses PERF event subsystem of kernel.
If you are using a Linux distro, then please check if "/sys/devices/cpu/type" file existing. If not existing, then the kernel-perf is not supporting the PMC events. This happens when the kernel is compiled with the config for "no-support for hardware events".