AttributeError: 'MegaError' object has no attribute 'format'

[kewei2019]

Hi,
When I used magalodon to call 6mA in GATC motif, an error came up:
megalodon fast5/ --outputs signal_mappings --reference E.coli_k-12_genome.fasta --devices 0 --processes 40 --ref-mods-all-motifs a 6mA GATC 1 --guppy-server-path ~/ont-guppy-cpu/bin/guppy_basecall_server

Do you know how to solve this?
Thank you so much!

Kewei Xu