I opened a old project and the library loaded fine but when the error box came up from the library manager saying what loaded and what was a duplicate it showed that everything from my library was missing that I added to the building (ie: doors, windows, objects). I am running ArchiCAD 12 and I just deleted the old files from ArchiCAD 11, including that AC11 library. Could that be what happened? And if it is where would I be able to find another AC11 library to download?