CryptographicEx ception, The parameter is incorrect.

[Tod Johnson]

Not so long I've found really strange bug in the .NET. It seems that
Evidence that I've got from the current executing Assembly is somehow
expired (it happens suddenly after about month) and Xslt Transformation
stop working at all for the whole AppDomain until I restart it. Am I
using "this.GetType() .Assembly.Evide nce" incorrectly? And another
question is what if I pass Evidence that I've created using
CreateEvidenceF orUrl(@"my working directory")? What is the diference
between this evidence and evidence that I've retrieved from Assembly
(this.GetType() .Assembly.Evide nce)?

Here is the code snippet:

XslTransform xt = new XslTransform();
try
{
xt.Load(new XmlTextReader(s tream), null,
this.GetType(). Assembly.Eviden ce);
}
catch(XsltCompi leException ex)
{
throw new Exception(Utils .ExceptionsToSt ring(ex), ex);
}

And here is the stacktrace:

Exception: System.Security .Cryptography.C ryptographicExc eption
Message: The parameter is incorrect.
Source: mscorlib
at System.Security .Policy.PolicyL evel.GenericRes olve(Evidence
evidence, Boolean& allConst)
at System.Security .Policy.PolicyL evel.Resolve(Ev idence evidence,
Int32 count, Char[] serializedEvide nce)
at System.Security .PolicyManager. Resolve(Evidenc e evidence,
PermissionSet request)
at System.Security .SecurityManage r.ResolvePolicy (Evidence evidence)
at System.Xml.Xsl. Compiler.Compil e(NavigatorInpu t input, XmlResolver
xmlResolver, Evidence evidence)
at System.Xml.Xsl. XslTransform.Co mpile(XPathNavi gator stylesheet,
XmlResolver resolver, Evidence evidence)
at System.Xml.Xsl. XslTransform.Lo ad(XPathNavigat or stylesheet,
XmlResolver resolver, Evidence evidence)
at System.Xml.Xsl. XslTransform.Lo ad(XmlReader stylesheet,
XmlResolver resolver, Evidence evidence)

Thanks in advance,
Tod