FSBTool64.exe crashed when import *.mp3

I have just updated unity from 5.1.3 to 5.5, and it noticed me that I must reimport project in unity 5.5.

But when I reimport .mp3 files, it always alert "FSBTool64.exe" crashed, and the message is :

Problem signature:

Problem Event Name: APPCRASH

Application Name: FSBTool64.exe

Application Version: 0.0.0.0

Application Timestamp: 57c57077

Fault Module Name: libvorbis64.dll

Fault Module Version: 0.0.0.0

Fault Module Timestamp: 53bf60f1

Exception Code: c0000005

Exception Offset: 0000000000004110

OS Version: 6.1.7601.2.1.0.256.1

Locale ID: 2052

Additional Information 1: 45a7

Additional Information 2: 45a751bf6bd9e389bab53cc7662e98f3

Additional Information 3: 9c3b

Additional Information 4: 9c3bd5ff08d4dc0ed4c125fe647e94ff

And there is a console output as:

Unspecified error during import of AudioClip Assets/Resources/audio/welcome.mp3

The mp3 setting in unity is :

Load Type: Decompress On Load

Preload Audio Data: checked

Compression Format: vorbis

Sample Rate Setting: Preserve Sample Rate

Quality: 100

Qriginal Size: 8.3kb

Imported Size: 4.5

Ratio: 54.38%

the bit rate of the mp3 file is 48kps.

The source audio file is .wav, but it's too big, so I transform it to .mp3.

I tried 2 kinds of software to transform the .wav file to .mp3, and tried 32kps/48kps/64kps/128kps, sometimes unity can import the .mp3 file all right, sometimes the FSBTool64.exe crashed randomly.

For example, a.wav transform to a.mp3(32kps), it's ok, but when transform to a.mp3(64kps), it crashed.
b.wav transform to b.mp3(32kps), it crashed, but when transform to b.mp3(64kps), it's ok......

I think it's something wrong with FSBTool64.exe.