I have a 3 TB disk that I have encrypted using Truecrypt 7.1a on Windows 7 x64. Recently, I had about 700 GB free and was moving about 200 GB of files to it. When the transfer was about 90 % complete Windows showed an error message that it wasn't possible to move a certain file since it was corrupt. I retried a couple of times and then skipped it. The rest of the transfer went ok.
After that, a lot of the files on the encrypted disk was unreadable. Some files still worked, and it wasn't just the newly moved files that was corrupted. After I had dismounted the disk and tried to mount it again Truecrypt wouldn't let me. Wrong password or not a Truecrypt volume.
After I restored the volume header from an external backup Truecrypt mounts the volume, but Windows says that the disk doesn't contain a recognized file system. This has happened once before, but I chalked it up to bad luck and maybe related to a re-installation of Windows, but now I know this isn't the case.
Does anyone have any idea about what went wrong and what I can do about it?