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There’s a general rule which says: never touch any managed reference-type object from within your finalizer. The rationale behind that idea is that you don’t whether the thing you’re touching had already been collected and finalized, thus making it unusable. This is even true for static objects, since you could be in the middle of shutdown.

There is, however, an exception to this rule (the only one I know of). Using the Console object is safe from your finalizer. The Design Guideline for Dispose, Finalization, and Resource Management has a small annotation by Brian Grunkemeyer which says:

Back during the implementation of V1.0, I was debugging a problem where a finalizer didn’t seem to be called. To help figure out if the finalizer was running at all, I added a call to Console.WriteLine inside it, but then my app started blowing up with an unhandled ObjectDisposedException. How could simply adding a call to Console.WriteLine to the finalizer break the app?

The problem turned out to be that the underlying console stream was being finalized before my instance. The lesson I learned was to follow this guideline: only use non-finalizable instance data from your own finalizer. But I also happened to own the code for the Console class, so I special cased Console.WriteLine—now we never close the handles for stdout, stdin, or stderr. This is somewhat useful for printf-style debugging and logging, and turned out later to be required to support multiple appdomains within the same process (i.e. you don’t want arbitrary appdomains closing your process-wide handle for stdout). So bottom line: using Console from your finalizer is actually a safe thing to do, but watch out for everything else.

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