NotImplementedError: "flankBed"

[YutingMa68]

Hi,when I used the outrigger software to do the variable splicing analysis, I got the following error. I haven't found a solution. I have to ask you. Can you help me find a solution?
NotImplementedError: "flankBed" does not appear to be installed or on the path, so this method is disabled. Please install a more recent version of BEDTools and re-import to use this method.
my python is python3.5

I have reinstalled the software and it has not solved this problem.

File "outrigger", line 6, in
sys.exit(outrigger.commandline.main())
File "commandline.py", line 1071, in main
cl = CommandLine(sys.argv[1:])
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/outrigger/commandline.py", line 344, in init
self.args.func()
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/outrigger/commandline.py", line 352, in validate
validate.execute()
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/outrigger/commandline.py", line 834, in execute
exonA, exonB, splice_abbrev)
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/outrigger/commandline.py", line 787, in exon_pair_splice_sites
exonA, splice_abbrev, 'downstream')
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/outrigger/commandline.py", line 800, in individual_exon_splice_sites
exon_bed, self.genome, self.fasta, direction)
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/outrigger/validate/check_splice_sites.py", line 57, in read_splice_sites
flanked = bed.flank(l=left, r=right, s=True, genome=genome)
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/pybedtools/bedtool.py", line 806, in decorated
result = method(self, *args, **kwargs)
File "/hwfssz1/ST_MCHRI/DISEASE/USER/liuhankui/bin/software/conda/envs/outrigger-env/lib/python3.5/site-packages/pybedtools/bedtool.py", line 204, in not_implemented_func
raise NotImplementedError(help_str)
NotImplementedError"flankBed" does not appear to be installed or on the path, so this method is disabled. Please install a more recent version of BEDTools and re-import to use this method.