I have (had) a large media library consisting of around 850 movies and over 2000 TV episodes. This evening I updated Yosemite to 10.10.4 and did the iTunes 12.2 update. Shortly afterwards, my daughter asked me where all the TV shows have gone. I checked iTunes and there are no TV shows there since 2013 and only 11 movies are showing. A quick check showed me that all the media source files are there, nothing has been deleted. I jumped into Time Machine and restored the following files from my backup which was taken before the updates. When I restarted iTunes, all my files were back. However, I watched them all disappear after a few seconds. I've followed the Apple instructions on recovering missing media files (basically restore the library file from Previous iTunes Libraries) but the same thing happens. iTunes starts, everything shows but after a few seconds it all goes away. It's as though iTunes opens, checks the library, deletes it and then creates a new version which has just a few of my media files but not all of them. Has anyone else experienced this today? Any advice or suggestions as to what I can do to fix it please. Thanks.