RuntimeError: LZ4F_decompress failed with code: ERROR_frameType_unknown.

[MindaugasVaitkus2]

I install python 3.7 and use code below from lz4 documentation to read mozzila firefox compressed json file to decompress to json file to extract bookmarks. I get error RuntimeError: LZ4F_decompress failed with code: ERROR_frameType_unknown.

import json
import os
import lz4.frame

testfile = "C:\Users\Vartotojas\application data\mozilla\firefox\Profiles\8zco1w2p.default-1520716267057\bookmarkbackups\bookmarks-2018-06-30_23_zKtuViq4dpuCfZ3hgk47jg==.jsonlz4"
testfile1 = "testfile_1.json"

input_data = 20 * os.urandom(1024)
with lz4.frame.open('testfile1', mode='wb') as fp:
bytes_written = fp.write(input_data)
bytes_written == len(input_data)

with lz4.frame.open(testfile, mode='r') as fp:
output_data = fp.read()
output_data == input_data

output_data = fp.read()

File "C:\Users\Vartotojas\AppData\Local\Programs\Python\Python37-32\lib\site-packages\lz4\frame_init_.py", line 635, in read
return self._buffer.read(size)
File "C:\Users\Vartotojas\AppData\Local\Programs\Python\Python37-32\lib_compression.py", line 103, in read
data = self.decompressor.decompress(rawblock, size)
File "C:\Users\Vartotojas\AppData\Local\Programs\Python\Python37-32\lib\site-packages\lz4\frame_init.py", line 398, in decompress
return_bytearray=self._return_bytearray,
RuntimeError: LZ4F_decompress failed with code: ERROR_frameType_unknown