Fatal error Unity 3D

hello I had downloaded the 4.0.1 unity so that I did not touch it and hence I removed the estlei Unity 3.5.2. Always when I push to start it appears Unity3D (Fatal Error type == kMetaAssetType && pathname.find (“Library/Metadata”) != 0)

You need to uninstall it using the designated uninstaller that came with your unity packet. Right now your versions are clashing, and you need to clean it up. Use the uninstaller and redownload.