I've got the same problem shortly after updating to Lolipop, the tablet doesn't boot up. First it was just permanently getting stuck at the Hudl logo stage but after doing factory reset it now loads up to the Hudl logo and then restarts itself. After a couple of restarts it automatically opens the recovery menu for me (without me pressing Volume Up button) so I guess it somehow realises it's broken. I tried the image from the links above but it says "E: failed to verify whole-file signature" and aborts the update. The android-build version in the tablet is 20150917.142239 so should match the version of the file (hudl2_ota_rel.android-build.20150803.092218_to_rel.android-build.20150917.142239.zip) but still doesn't work for me due to this "signature verification failed" error. Any ideas if the tablet can be fixed at all? Sadly it passed the 1 year warranty recently, otherwise I'd just return it to Tesco :( The tablet has never been rooted.