New containers won't mount

[Paul Fullname]

Cannot mount newly created drive or containers.

I first encrypted a compete external USB3 HDD ( 1TB) and after a couple hours it finished successfully.

PW: 20 charactors
PIM: 4 digits
KeyFile: (yes)

Would not mount saying the usual "password/keyfile/PIM/volumn incorrect" error.

I reformatted to a new NTFS partition and tried to create a container in that partition instead.

Process to make an encrypted container succeeded.

Same problem, cannot mount.

I had all the login saved in a text file to copy/paste to avoid typos so I am certain after multiple attempts to mount that was NOT incorrect?

Of course they are empty so no data at risk because I cannot even open to add data.

[Adrian Kentleton]

Did you create a keyfile, or choose an existing file as a keyfile?

[Paul Fullname]

I used a keyfile that is existing and that keyfile works fine on other containers so it is not corrupted. ( I have backups just in case )

I started over. I used Bitlocker on the HDD then created a VeraCrypt container inside the Bitlocked drive. Works fine using exact same key file I tried when attempted to encrypt the partition.

Problem worked around but the cause of the problem remains unknown.

Thanks