Getting MP4MetadataError: unpack requires a string argument of length 4 on files previously tagged

error
picard
Tags: #<Tag:0x00007f23c6bb5350> #<Tag:0x00007f23c6bb4ba8>

#1

Seems like I can tag it, but all previous tags are gone. How do I prevent this?

E: 04:14:56 Traceback (most recent call last):
File “picard\util\thread.pyo”, line 46, in run
File “picard\file.pyo”, line 116, in load_check
File “picard\formats\mp4.pyo”, line 115, in load
File “mutagen_file.pyo”, line 48, in init
File “mutagen_util.pyo”, line 123, in wrapper
File "mutagen\mp4_init
.pyo", line 1018, in load
File "mutagen\mp4_init
.pyo", line 1014, in load
File “mutagen\mp4_init_.pyo”, line 329, in init
File “mutagen\mp4_init_.pyo”, line 349, in load
File “mutagen\mp4_init_.pyo”, line 579, in __parse_freeform
File “mutagen_util.pyo”, line 514, in
MP4MetadataError: unpack requires a string argument of length 4


#2

I was wrong, when I try to save tags I get similar error.

E: 04:22:00 Traceback (most recent call last):
File “picard\util\thread.pyo”, line 46, in run
File “picard\file.pyo”, line 210, in save_and_rename
File “picard\formats\mp4.pyo”, line 167, in save
File “mutagen_file.pyo”, line 48, in init
File “mutagen_util.pyo”, line 123, in wrapper
File "mutagen\mp4_init
.pyo", line 1018, in load
File "mutagen\mp4_init
.pyo", line 1014, in load
File “mutagen\mp4_init_.pyo”, line 329, in init
File “mutagen\mp4_init_.pyo”, line 349, in load
File “mutagen\mp4_init_.pyo”, line 579, in __parse_freeform
File “mutagen_util.pyo”, line 514, in
MP4MetadataError: unpack requires a string argument of length 4