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