Where are you located and what kind of climate do you have there?

In any case get rid of the old insulation and then seal the dirt by covering with 6 mil plastic. Concrete over that if feasible. Use a dehumidifier to reduce the moisture in the crawl space.

I have a dehumidifier running now in a Michigan basement and the musty smell is almost gone. The dial read 90% to start with and is down to 65%. It took a week.

Home is on Table Rock Lake Missouri/Arkansas border. HUMID but not severe cold..

Bat insulation under the floor in air conditioned homes in humid environments is generally a bad idea. You will be lucky if you only have mold and not rotten floors. Air leaks past the bats and water condenses on the subfloor and on the joists.

Fix the floor. If the crawlspace is not sealed, it might make sense to seal it from the outside. Check with a local energy rater or building expert. (First, check into it yourself. Sometimes it can be difficult to find people with up to date knowledge. http://www.buildingscience.com is a good resource.) There might be more moisture available from the air than from the ground. Alternatively, use open-cell spray foam under the floor to replace the glass.