ERROR: user-space process-tracking facilities not available
occurs when the script contains a uprobes probe point that the current kernel does not support.
WARNING: process-tracking facilities are not available in this kernel
and the related message,
WARNING: cannot track target in process '...'
both occur at runtime when running on a kernel (generally an older version) that has neither utrace functionality nor an acceptable substitute.
The script should still load and run. However, probes that rely on availability of process-tracking facilities will silently fail to trigger.