TrueCrypt device that was mountable on Win7 not mountable on LinuxMint

[LittleGravitas]

Hello community,

I am new to Linux Mint and have a problem I cannot find any answers to on the web.
I switched from Windows 7 and have a second HDD that is encrypted with Truecrypt as a “device”. When planning to switch to Linux, I learned Truecrypt was discontinued, but Veracrypt took over the mantle. While I was still on Windows, I checked if I could mount my encrypted device/HDD on Veracrypt too, and using the “Truecrypt mode” this worked.

But using Veracrypt now after I switched to Linux Mint, mounting the HDD does not work any more and I don’t understand why.

First, I have 4 entries to choose from when I want to select the device I want to mount.
dev/sdb
dev/sdb1
dev/sdb2
dev/sdb3

Second, no matter which one I choose, I get the error

Operation failed due to one or more of the following:
- Incorrect password.
- Incorrect Volume PIM number.
- Incorrect PRF (hash).
- Not a valid volume.

1.: I can rule out the incorrect password one since I successfully mounted the device on Windows.
2.: Volume PIM number seems to not apply to Truecrypt containers.
3.: Incorrect PRF (hash) seems the most likely, but I do not understand enough about security to have an idea what I could do about that.
4.: Not a valid volume – maybe because these 4 entries by themselves are not valid volumes? I know the HDD is a valid volume, but maybe being in a Linux context Veracrypt fails to recognise it as such?

I also tried using the option "Use backup header embedded in volume if available", with no different outcome.

Regarding point 4, I had a hunch that maybe the HDD needs to get registered or somesuch, so I had a look at the device in Gparted.
In there, I see each “sub partitions” (?) having assigned a descriptive name:
dev/sdb1 – LDM metadata partition
dev/sdb2 – Microsoft reserved partition
dev/sdb3 – LDM data partition

Sounds like useful info, but I am at a loss how to use that.

The VeraCrypt option “Restore Volume Header” seems tempting, but since I cannot create a "Volume Header backup" (it requires the password and then throws the same error as above), I am a bit reluctant to mess with the header when I don’t really understand the underlying issue.

My questions are:
What is the problem?
Is this fixable, if yes how?

I read you like inxi outputs, so I’ll post what I guess is useful wrt to my HDD and system situation:

System:
Host: NB Kernel: 4.15.0-58-generic x86_64 bits: 64 compiler: gcc
v: 7.4.0 Desktop: Cinnamon 4.2.3 Distro: Linux Mint 19.2 Tina
base: Ubuntu 18.04 bionic

Drives:
Local Storage: total: 803.71 GiB used: 223.12 GiB (27.8%)
ID-1: /dev/sda vendor: Intel model: SSDSA2CW160G3 size: 149.05 GiB
ID-2: /dev/sdb vendor: Samsung model: HM500JI size: 465.76 GiB
Partition:
ID-1: / size: 144.73 GiB used: 22.73 GiB (15.7%) fs: ext4 dev: /dev/dm-0
ID-2: swap-1 size: 976.0 MiB used: 0 KiB (0.0%) fs: swap dev: /dev/dm-1

[SprinterDriver]

I beleive you have just forgot to activate the "Truecrypt mode" before trying to mount.

[LittleGravitas]

I beleive you have just forgot to activate the "Truecrypt mode" before trying to mount.

Unfortunately, no.

I tried to mount the device under Windows again - and it didn't work now either! So my best guess is that the Linux installation process altered something important in some way.
Since I wanted to proceed (this thing needs to be running by beginning of next week) I wiped the HDD yesterday and restored data from backups.

So I don't need help any more to fix this, but I'd still be curious what went wrong - this experience seemed rather random.

[OunceofCommonSense]

You might be better off using https://www.veracrypt.fr/en/Downloads.html a more updated and secure version of Truecrypt. I believe Truecrypt is not supported and has not been for a few years