XML Schema throwing permission failed warning

I have an xml document and schema and when I open the xml document in visual studio I get a bunch of warnings like:

Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561开发者_运维技巧934e089' failed.

Does anyone know what might be the cause of these warnings? It is making it difficult to validate the xml document. Also when I hover over the squiggly line under the schemaLocation attribute value, the tool tip gives the error "The schema referenced from this location in your document contains errors"

Thanks in advance!

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Turns out this is a Visual Studio specific problem. I loaded the xml document in Altova's XMLSpy and it worked just fine.