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I have three shapefiles and two buffers made from two separate shapefiles. I was trying to do a spatial join and it kept coming up with an empty file even though there was clearly overlap. I realized that some of the shapefiles had different projections. I changed them all to NAD 1984 for zone 18 and I also tried WGS, and then GCS WGS, but two of the shapefiles and a buffer file are now unaligned with a shapefile and its buffer. They are all the same coordinate system and they aren't aligning when they were before I changed the coordinate system. Is there a way to change them back? The undo button just says "remove layer." Or suggestions to fix this? I don't want to start from scratch with the original data.