I'm using FileHelpers for reading csv files, and all it was ok until I switched from VS dev server to IIS, I get a "PolicyException: Required permissions cannot be acquired", I googled and found that I need to add Reflection Permission for this to work, anybody knows how ?
It sounds like you're running in partial trust. If your production environment is running in full trust, just update your dev environment to run in full trust. However, if you're trying to simulate your production environment, then here's how to change it:
Go to your framework folder/config. Find out which trust level you're on. i.e. medium, full, etc. That may be set in your site's web.config, or the framework's root web.config.
Whatever you do in dev, you'll need to do in production to. So the first step is to setup your dev like production. Then, if production is medium trust (for example), you'll need to either update the web_mediumtrust.config file or create a copy of it as a custom policy. Use the syntax in the root web.config file to see how to define it. Search for keyword 'trust'.
Add the following to your trust template:
where Flags is a comma delimited list of specific permissions.
Make sure to get approval to have the same settings pushed to production too.
Is any of the assembly you use located on a network share? If yes than: