bug#46539: Assertion (start >= 0) at cs/geom.c:157 in function ped_geometry_set() failed.

I managed to fix the issue by using "fdisk" and delete all corrupted
partitions from number 20 to 64.

After that, Parted and GParted worked again:

$ sudo parted /dev/sdb
GNU Parted 3.3
Using /dev/sdb
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted) p
Model: ATA KINGSTON SA400S3 (scsi)
Disk /dev/sdb: 240GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:

Number  Start   End     Size    File system  Name
 Flags
 1      1049kB  17,8MB  16,8MB               Microsoft reserved partition
 msftres
 2      17,8MB  240GB   240GB   ntfs         Basic data partition
 msftdata
 3      240GB   240GB   533MB   ntfs
hidden, diag
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And so does "gdisk":

$ sudo gdisk /dev/sdb
GPT fdisk (gdisk) version 1.0.5

Partition table scan:
  MBR: protective
  BSD: not present
  APM: not present
  GPT: present

Found valid GPT with protective MBR; using GPT.

Command (? for help):
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Thanks,
Samuel Phan