got an error. The version has reinstalled, but still does not work;

qt.qpa.plugin: COULD NOT FIND THE QT PLATFORM PLUGIN “Windows” IN “”
This Application Failed to Start Because No Qt Platform Plugin Could Be Initialized. Reinstalling the Application May Fix This Problem.

import sys
From Pyqt5 Import Qtcore, Qtgui, Qtwidgets
From Test Import UI_Dialog
#Create App.
App = Qtwidgets.Qapplication (SYS.Argv)
#init.
Dialog = qtwidgets.qdialog ()
UI = ui_dialog ()
UI.Setupui (Dialog)
Dialog.show ()
#Main Loop.
sys.exit (app.exec_ ())

Answer 1, Authority 100%

When you start the application in the application directory, it must lie. \ Platforms \ qwindows.dll