RS Custom Code (Permission Errors)

I created some custom code that will check to see if a file exists on a Windows Share.



Code Snippet
Public Function FileExists(ByVal FileFullPath As String) As Boolean
Try
Dim f As New System.IO.FileInfo(FileFullPath)
Return f.Exists
Catch e As Exception
Return e.Description
End Try
End Function





An example of what I am passing is this:



Code Snippet
\servernamesharenamefilename.txt





I use this code in a TextBox on my Report:



Code Snippet
=IIF(Code.FileExists(Fields!OutPutFileName.Value) = TRUE,"True","False")





I get this error in my report:



Code SnippetSystem.Security.SecurityException: Request for the permission of type 'System.Security.Permissions.FileIOPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
at System.Security.CodeAccessSecurityEngine.Check(Object demand, StackCrawlMark& stackMark, Boolean isPermSet)
at System.Security.CodeAccessPermission.Demand()
at System.IO.FileInfo..ctor(String fileName)
at ReportExprHostImpl.CustomCodeProxy.FileExists(String FileFullPath)
The action that failed was:
Demand
The type of the first permission that failed was:
System.Security.Permissions.FileIOPermission
The Zone of the assembly that failed was:
MyComputer




BUT it works on my local machine. Any Ideas?