C6678 mpeg2 decoder TEST project compiling errors

I downloaded  6678 mpeg2 decoder codec TEST Project from link below:
http://software-dl.ti.com/dsps/dsps_public_sw/codecs/C6678_Video_Codecs/01_00_001/index_FDS.html

I followed the User’s Guide --MPEG2_Decoder_C6678_UserGuide.pdf
in the DIR
\Codecs\C66x_mpeg2vdec_02_02_00_02_ELF\packages\ti\sdo\codecs\mpeg2vdec\Docs

My BIOS ,XDCTOOLS, Framework Components and BIOS IPC version was below:

DSP/BIOS version 6.31.00.18,
Bios IPC version 1.22.04.25,
XDC Tools version 3.20.08.88 &
Framework Component (FC) version 3.20.02.29.

My CCS version was CCS5.4

But when I set envionment variables already and compiled mpeg2 decoder TEST project.I met the error:

Buildfile generation error occurred..
This project was created using a version of XDCtools that is not currently installed: 3.20.8.88. Please install the XDCtools of this version, or migrate the project to one of the supported versions.
Build stopped..

Who can tell me why the error comes even though I followed the User’s Guide settings?
Any help will be appreciated.Thanks!