Hi,
I'm assuming you have a YouView box and not the 4k one that uses a usb to record.
If so have you tried a soft reset? To do this hold the power button on the front for around 10 seconds and the box should restart.
If this doesn't work then have you tried a YouView Maintenance Reset (https://community.talktalk.co.uk/t5/Articles/How-to-find-maintenance-mode/ta-p/1429347)?
Try the Factory Reset keep recording option.
You will then need to reset your personal settings (such as parental controls / Set antenna Out to On in Settings: Picture and Sound / Surround Sound etc.) and also reset your scheduled recordings (might be worth taking a note of future recordings before doing this so you don’t miss any).
If all else fails then try a full factory reset from the settings menu you've just used above. You will lose your recordings but you may be asked to do this before the Support Staff look at other alternatives.
TalkTalk now only supply non-recordable boxes, So it's best to try all alternatives if recording is important to you.
You will need to phone and probably re-contract to obtain a new box, but as said it will be non recordable.
Hope it works and please let us know how you get on.
Please remember to mark Solved Posts with Best Answer. Doing so helps other customers and saves TalkTalk's Support Team time by only looking at unsolved topics. Thanks, Steve (a fellow customer).
