The error System.Security.Policy.PolicyException: Required permissions cannot be acquired was encountered on a Helm managed system for ASP .NET2 when attempting to use the ChilkatDotNet2.dll .

This post describes an error received when trying to use some 3rd party DLLs. The article listed below describes this situation in full –

Some DLLs require Full Trust because they contain unmanaged code, or communicate via TCP/IP sockets in various protocols: FTP, HTTP, POP3, SMTP, IMAP, etc. In this case, setting a strict Medium Trust will cause a failure.

http://www.chilkatsoft.com/p/p_243.asp

The fix is to assign the specific DLLs higher than Medium Trust. The procedures are discussed here for Chillkat Components:

http://www.chilkatsoft.com/p/p_116.asp

Relevant quick facts:

• On a default Helm configuration, the file to edit is web_mymediumtrust.config
• Location of this file is at: C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG
• PublicKeyBlob is needed if this procedure is repeated for other DLLs.