Asp.net mvc 4 Amazon S3加密数据失败

API正在开发中，但尚未投入生产。 我已经上传了所有的DLL文件和网页配置上的密钥了

我还有别的事要做吗

代码如下：

Amazon.Util.ProfileManager.RegisterProfile(bucket, key, secret);
using (IAmazonS3 s3Client = new AmazonS3Client(credentials, RegionEndpoint.USEast1))
{
    // Setup request for putting an object in S3.
    PutObjectRequest request = new PutObjectRequest
    {
        BucketName = bucketfolder,
        Key = key,
        InputStream=file,
        ContentType = "image/jpeg",
        CannedACL=S3CannedACL.PublicRead
    };
    // Make service call and get back the response.
    PutObjectResponse response = s3Client.PutObject(request);
    return response.HttpStatusCode;
}

这是一个例外：

Amazon.Runtime.AmazonClientException: CryptProtectData failed. ---> System.ComponentModel.Win32Exception: The system cannot find the file specified
   --- End of inner exception stack trace ---
   at Amazon.Runtime.Internal.Settings.UserCrypto.Encrypt(String unencrypted)
   at Amazon.Runtime.Internal.Settings.SettingsCollection.ObjectSettings.WriteToJson(JsonWriter writer)
   at Amazon.Runtime.Internal.Settings.SettingsCollection.Persist(StreamWriter writer)
   at Amazon.Runtime.Internal.Settings.PersistenceManager.saveSettingsType(String type, SettingsCollection settings)
   at Amazon.Util.ProfileManager.RegisterProfile(String profileName, String accessKeyId, String secretKey)
   at project.AWS.s3.upload(String file, String key)