If you guys are seeing a Tome error when installing then there's probably an issue with the downloaded files.These can be incomplete if the downloader wasn't able to finish.Whether you repair your previous install or download the entire game again, it's necessary to use this new downloader to install and play the game when it launches.
installers start running today (even though you can install the game, you can't play until midnight PST), a host of issues have cropped up.Most of these can be solved by commonsense troubleshooting techniques, but some others are a bit more .If it's asking for a disk then it means an entire data tome is missing from the download.I'd recommend restarting the downloader to see if you can pick that up.Though the downloader may show 100%, please allow some time for it to fully complete.
You may be able to fix this by running the downloader and pointing it to the same saved location so that it may scan and download any missing files. We became aware of an issue affecting the previously available German and EU English versions of the digital install downloader for Diablo III, which would not download all the necessary files.
Point the download save at the same directory as before The folder in question is your main game data folder.
If you have the game downloaded to D:\Games\Diablo-III-8370-en GB-Installer, please point the download to D:\Games\.
We'll keep this post updated throughout the next couple of days with the latest problems and info on how to fix them.
We'll also include non-Blizzard sources when appropriate (but in general, Blizzard is pretty on top of all these).
As has been mentioned, launching the Diablo 3 downloader and directing it to the same folder as before will allow it to download the installer files again.