Authentication File : Error when using "drag & drop"

When trying to login using this file using a "drag & drop"

platform.js:85 TypeError: Failed to execute 'readAsText' on 'FileReader': parameter 1 is not of type 'Blob'.
    at crypto-services.js:161
    at Q (ionic.bundle.js:29391)
    at CryptoAbstractService.readKeyFile (crypto-services.js:144)
    at Scope.LoginModalController.$scope.doLogin (login-controllers.js:122)
    at fn (eval at compile (ionic.bundle.js:27638), <anonymous>:4:212)
    at callback (ionic.bundle.js:38178)
    at Scope.$eval (ionic.bundle.js:30395)
    at Scope.$apply (ionic.bundle.js:30495)
    at HTMLFormElement.<anonymous> (ionic.bundle.js:38183)
    at defaultHandlerWrapper (ionic.bundle.js:16787)