Under level properties untick grenerate wac, this will stop nile from over writing you hand writen wac file, but make sure u do all your other events u want to do with nile first then hand edit it, if generate wac is unticked nile will not ova write hand writen wacs it but it will also not generate any other events u have done in nile after its been unticked, so once u have done everything else u want to do in nile, untick genreate wac so it cant be ova writen if u have to open nile again to do something.
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