Improve error handling in resource serialization

[Jummit]

This adds some error printing when resources couldn't be serialized to make it easier to track down. In some cases it also prevents corrupting the resource by skipping elements that couldn't be serialized.

This is a little heavy-handed, as it sometimes bubbles up errors instead of trying to move on. I don't think this should be a problem in most cases. It's also noteworthy that this isn't a very uniform change. It just touches the code path's that caused me issues.

If this is too verbose please let me know.

Partially addresses #62276 by telling the user that a variant couldn't be serialized.