Examples of this error are
Process does not have permission to Read the Windows Registry.
Using PDFNet in demo/trial mode on development machines is usually not a problem because they are typically configured to have a loose security policy.
However, in case you are using the evaluation version on a production IIS server, you need to grant full permissions to the assembly - or loosen your global security policy.
Some of our customers were able to use the demo on servers with tight
security by modifying a config xml file that controls security
settings or using
Code Access Security Policy tool. For more info
Because there are many different machine configurations and because the demo is not intended to be run in the production environment, we are not actively supporting this use case scenario.