The encryption within GRF Editor will work perfectly fine, but you're probably having compatibility issues from the client (caused by the protection used on the DLL; only a few version of clients will be able to use this encryption system). There's also a bug that will make it impossible to patch with the current patchers (such as Thor Patcher). So for now, I simply wouldn't use the encryption feature. I'm going to fix this so that it works for any client, but that's going to be in a couple months when I'm not as busy as I am right now. Basically : do not encrypt your files with GRF Editor.
OK, thanks for Reply~