Adding a large external disk

It is SD as far as I know (not in front of TV now) and looking through the WebIF the original and copied file shows SD, though it also shows no decrypt symbol and the flags are -

[edit: I think I may be going mad and had not used opt+ like I thought]
Sorry. I must remember not to attempts things like this (or at least not post about them) while rushing around and trying to keep an eye on a wobbly 'cruising' 8 month old. So distracted I don;t actually know what I am doing.

So, I've just done another test. Copying using opt+ to the external drive and it all plays OK. So I must have done the other test from the webif (many apologies) and that's why it is not decrypted. That does raise the issue that I was planning to move them over mostly using the webif and that's not going to work without decrypting them first. But is good for the long term as it means the Humax i/f my wife uses will all work without any trouble or extra steps.
Even an encrypted file should play from an external drive, as long as the sidecar files go with it.