Security Exception error

I have a web application for upload video and images.In local server that working perfectly.But when i uploaded this to web server there is a error and i can't upload the files.The error is

Security Exception 
Description: The application attempted to perform an operation not allowed by the security policy.  To grant this application the required permission please contact your system administrator or change the application's trust level in the configuration file. 

Exception Details: System.Security.SecurityException: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.

Source Error: 

The source code that generated this unhandled exception can only be shown when compiled in debug mode. To enable this, please follow one of the below steps, then request the URL:

1. Add a "Debug=true" directive at the top of the file that generated the error. Example:

  <%@ Page Language="C#" Debug="true" %>

or:

2) Add the following section to the configuration file of your application:

<configuration>
   <system.web>
       <compilation debug="true"/>
   </system.web>
</configuration>

Note that this second technique will cause all files within a given application to be compiled in debug mode. The first technique will cause only that particular file to be compiled in debug mode.

Important: Running applications in debug mode does incur a memory/performance overhead. You should make sure that an application has debugging disabled before deploying into production scenario.  

[SecurityException: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.]
   System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boolean isPermSet) +0
   System.Security.CodeAccessPermission.Demand() +58
   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) +644
   System.IO.FileStream..ctor(String path, FileMode mode, FileAccess access, FileShare share, Int32 bufferSize, FileOptions options, String msgPath, Boolean bFromProxy) +61
   System.IO.FileStream..ctor(String path, FileMode mode) +55
   System.Web.HttpPostedFile.SaveAs(String filename) +99
   System.Web.UI.WebControls.FileUpload.SaveAs(String filename) +23
   Uploader.VideoUpload.ButtonUpload_Click(Object sender, EventArgs e) +195
   System.Web.UI.WebControls.Button.OnClick(EventArgs e) +111
   System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +110
   System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13
   System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +6785
   System.Web.UI.Page.ProcessRequest(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +242
   System.Web.UI.Page.ProcessRequest() +80
   System.Web.UI.Page.ProcessRequestWithNoAssert(HttpContext context) +21
   System.Web.UI.Page.ProcessRequest(HttpContext context) +49
   ASP.forms_videoshow_aspx.ProcessRequest(HttpContext context) +37
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +181
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +75

I am using the code for uploading is..

Dim connectionstring As String = ConfigurationManager.ConnectionStrings("UploadConnectionString").ConnectionString
                 开发者_如何学JAVA   connection = New SqlConnection(connectionstring)
                    Dim cmd As New SqlCommand("insert into FileM (FileName,[File],FilePath,FileSize)" + "values(@FileName,@File,@FilePath,@FileSize)", connection)
                    cmd.Parameters.Add("@FileName", SqlDbType.NVarChar, buffer.Length).Value = FileUpload1.FileName
                    cmd.Parameters.Add("@File", SqlDbType.VarBinary).Value = buffer
                    cmd.Parameters.Add("@FileSize", SqlDbType.BigInt).Value = file.ContentLength
                    cmd.Parameters.Add("@FilePath", SqlDbType.VarChar).Value = path
                    Using connection
                        connection.Open()
                        Dim i As Integer = cmd.ExecuteNonQuery

                    End Using

There have any issue with this type of uploading or want to insert into table via bussiness logic layer?

---

You need to grant write permissions to the folder on the server. If it's a Windows Server, grant the permissions to "Network Service".