Restricted assembly loading issue. How to solve?

Warning: This form's code is attempting to load a restricted assembly. For security reasons, this functionality is only available to full trust forms. Please contact your administrator or the form designer.

Assembly name: CommonPageExecutionLogic, Version=1.0.0.0, Culture=neutral, PublicKeyToken=e871dc6aeced41ec.

This is the message which appears when trying to view this form. As an exception equavalent it looks like "The thread was being aborted".

The most interesting part of the show is that on another server this form opens without problems.

What policies am I to configure to allow loading this assembly?

Sincerely yours, Andreas

[759 byte] By [Andreas] at [2008-3-7]