intel_pt data cannot be imported properly into Intel VTune 2018 - intel

Question

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 for `libprocps.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 for `vmlinux'
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?