The past couple of days, we've been getting this error quite randomly on our production environment:

The type initializer for 'Tridion.ContentManager.Templating.Expression.JScriptEvaluator' threw an exception.

Like I said, it seems to happen randomly, with different type of components and/or pages and independent of target. I cannot reproduce it on another environment or by previewing the items. I'm thinking of contacting CS, but thought I might as well try here first...