Reverting Back from a Snapshot Causes Corruption

When I opened up my world to test out the snapshot, then reverted back to 1.7.9 so that I can continue my work. The world became corrupted. Chunks corrupted, redstone was deleted all my builds in the loaded chunks were ruinined. This really sucks because I put a lot of hard work into it, so please fix. Thanks. I believe this is a problem with changing data tags, but I am no expert.