intel_pt data cannot be imported properly into Intel VTune 2018

I am using Intel VTune 2018 to profile and derive the control flow dependencies by making use of the Intel_PT PMU under the system:

Kernel: 4.15.0-13-generic, 64bit Ubuntu

CPU: Intel® Core™ i7-7820X @ 3.60GHz × 16

I started with the following commands:

1- amplxe-perf record -o a.perf -T -e intel_pt// -- ps

PID TTY TIME CMD 21471 pts/1 00:00:00 amplxe-perf 21472 pts/1 00:00:00 ps 58693 pts/1 00:00:00 sudo 58694 pts/1 00:00:00 su 58695 pts/1 00:00:00 bash [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 3.154 MB a.perf ]

2- amplxe-cl -import a.perf -r folder

amplxe: Importing a new result 100 % done
amplxe: Using result path /home/amad/May2/folder' amplxe: Executing actions 12 % Loading 'a.perf' file
amplxe: Error: Cannot load data file/home/amad/May2/folder/data.0/a.perf' (Data file is corrupted). amplxe: Executing actions 50 % done
amplxe: Error: 0x4000001e (Cannot load raw collector data)

Although intel_pt data has not been successfully imported, the data for other kernel PMU events like "cpu-cycles" and "instructions" could be properly handled:

1- amplxe-perf record -o p.perf -T -e cpu-cycles,instructions -- ps

PID TTY TIME CMD 8410 pts/0 00:00:00 sudo 8458 pts/0 00:00:00 amplxe-perf 8467 pts/0 00:00:00 ps [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.024 MB p.perf (96 samples) ]

2- amplxe-cl -import p.perf -r r2

amplxe: Importing a new result 100 % done
amplxe: Using result path /home/amad/r2' amplxe: Executing actions 19 % Resolving information forlibprocps.so.6.0.0'
amplxe: Warning: Cannot locate debugging information for file /lib/x86_64-linux-gnu/libprocps.so.6.0.0'. amplxe: Executing actions 21 % Resolving information forvmlinux'
amplxe: Warning: Cannot locate debugging information for the Linux kernel. Source-level analysis will not be possible. Function-level analysis will be limited to kernel symbol tables. See the Enabling Linux Kernel Analysis topic in the product online help for instructions. amplxe: Executing actions 75 % Generating a report

Collection and Platform Info

Parameter r2

---

Operating System 4.15.0-13-generic
Computer Name amad-pc
Result Size 2766877
Collector Type Driverless Perf per-process sampling

CPU

Parameter r2

---

Frequency 3600000000 Logical CPU Count 16

Summary

Elapsed Time: 0.011 Paused Time: 0.0
CPU Time: 0.011 Average CPU Utilization: 0.897

Event summary

Hardware Event Type Hardware Event Count:Self Hardware Event Sample Count:Self Events Per Sample

---

cpu-cycles 40521584 45 4000
instructions 36302909 51 4000
amplxe: Executing actions 100 % done

What is wrong with Intel_pt data?

Thanks