Throwing Exception when saving image in File Server

See more:

IIS7

C#

IIS

Hi,

When i am trying save the image in the server it's throwing below error.

A generic error occurred in GDI+. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.Runtime.InteropServices.ExternalException: A generic error occurred in GDI+.

Source Error: 


Line 166:                                    if (objFileUpload.impersonateValidUser())
Line 167:                                    {
Line 168:                                        ImgThnail.Save(Path.Combine(objFileServerImpersonation.FileServerPath(), ThumbnailPath), Img.RawFormat);
Line 169:ImgThnail.Dispose();

i am using impersonate method to validate user credentials to check get the permissions from the server.