I was also suffering from same problem, but there is a solution for it.
Go to the IIS server, and then to the application pool from which your application is running. In the advanced settings of the application pool there is a "Process Model" option, under which there is an "Identity" option. This is by default the application pool identity. Change it to Local System, and you're done.
And Remember to Put App_Data Folder their in WWW folder of IIS server
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