I have installed Android Studio version 1.0.1. I have imported my projects from eclipse and it works fine. Then I deleted a module and reimported it into my Android Studio p
Although the accepted answer didn't work for me (unfortunately I can't leave a comment), it led me in the right direction.
in .idea/libraries i found that there were some duplicate xml files (the duplicates were named with a 2 before the _aar.xml bit).
deleting those, restarting android studio and sync fixed the error