Diablo 3 “Error 108 occurred. It’s unable to open installer tome2.mpqe.”
This issue is likely caused by partial or incomplete files. To resolve this issue, try these steps:
1. Launch the downloader again.
2. Point to the directory which contains Diablo-III-8370-enGB-Installer to verify game files and correct any missing data. The folder in question is your main game data folder. If you have the game downloaded to D:\Games\Diablo-III-8370-enGB-Installer, please point the download to D:\Games\. Do not use the automatically generated folder containing the installation files (i.e. do not use the directory D:\Games\Diablo-III-8370-enGB-Installer as this is the one created by the downloader).
3. Allow the downloader to sit at 100%; it should eventually launch the installer automatically. Please do not close the downloader manually, it will close itself automatically when operations are complete.
Alternately, delete the Diablo III client and re-download the installer via Battle.net.