URGENT. Permission to access files in between sites

Hi,

We have two websites, A and B. published in internet.

Website A will access files from website B.

Initially it was working fine. but this days there was some server manintance and from then.

Site A is unable to access files from B.

Server team suggested us to provide Trusted level in web.config.

We tried the options in below link, but it was not working.

http://msdn.microsoft.com/en-us/library/wyts434y%28v=vs.100%29.aspx

Please Suggest, are we missing something?

Below error occures.

[SecurityException: Request for the permission of type 'System.Net.WebPermission, System, 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.Net.HttpWebRequest..ctor(Uri uri, ServicePoint servicePoint) +147 System.Net.HttpRequestCreator.Create(Uri Uri) +26 System.Net.WebRequest.Create(Uri requestUri, Boolean useUriBase)+216 System.Net.WebRequest.Create(Uri requestUri) +31

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