I redownloaded the game and when i opened the launcher there were a message "send the crashlog.txt to the developers", then i opened the game folder and this is the crashlog.txt:   
[04/06/2018 12:52:04] Exception System.UnhandledExceptionEventArgs, Base path C:\Users\adria, Info System.IO.IOException: O processo não pode acessar o arquivo 'C:\Users\adria\Desktop\T K\PandaWoW 5.4.8\PandaWoW-64.exe' porque ele está sendo usado por outro processo. 
   em System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath) 
   em System.IO.FileStream.Init(String path, FileMode mode, FileAccess access, Int32 rights, Boolean useRights, FileShare share, Int32 bufferSize, FileOptions options, SECURITY_ATTRIBUTES secAttrs, String msgPath, Boolean bFromProxy, Boolean useLongPath, Boolean checkHost) 
   em System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share) 
   em System.IO.File.OpenRead(String path) 
   em Launcher.MainWindow.Client_DownloadStringCompleted(Object sender, DownloadStringCompletedEventArgs e) 
   em System.Net.WebClient.OnDownloadStringCompleted(DownloadStringCompletedEventArgs e) 
   em System.Net.WebClient.DownloadStringOperationCompleted(Object arg) 
   em System.Threading.QueueUserWorkItemCallback.WaitCallback_Context(Object state) 
   em System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) 
   em System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean preserveSyncCtx) 
   em System.Threading.QueueUserWorkItemCallback.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem() 
   em System.Threading.ThreadPoolWorkQueue.Dispatch() 
   em System.Threading._ThreadPoolWaitCallback.PerformWaitCallback()   
I dont know what it means, anyway just follow what laucnher told