0x80070057 error when decrypting drive with bitlocker

TL;DR trying to decrypt a drive using manage-bde -off g: spits out this error:

ERROR: An error occurred (code 0x80070057):
The parameter is incorrect.

got a laptop with a broken screen, i disabled bitlocker protection on the drive, shut it down and swapped it to a new chassis, error upon boot, cannot find boot partition or some such. windows startup repair fails. none of the bootrec, chkdsk or sfc commands do anything to repair the partition. i assumed maybe bitlocker is preventing repairs from running. i try to decrypt the drive and get the above error. curent drive status:

Volume G: []
[Data Volume]

    Size:                 Unknown GB
    BitLocker Version:    Windows 7
    Conversion Status:    Fully Encrypted
    Percentage Encrypted: 100%
    Encryption Method:    AES 128 with Diffuser
    Protection Status:    Protection Off
    Lock Status:          Unlocked
    Identification Field: None
    Automatic Unlock:     Enabled
    Key Protectors:
        Numerical Password
        TPM
        Password
        External Key (Required for automatic unlock)

any ideas on what that error could mean? apparently when encrypting it means you're missing an active volume, but i'm doing the opposite and there is another active volume on that disk that's just fine.