Thank you ,i know why BTSync didn't run,because the config file , // path to folder where Sync will store its internal data, // folder must exist on disk "storage_path" : "/Users/user/.SyncAPI", i set this use the folder that on my disk,before i didn't notice this option,now BTSync can start! right setting is : "storage_path" : "your disk's folder",//the folder must exist on your disk