Hahaha, I opened this post thinking it was about a boulder called "Found Birkenstock" and pondered on the "beta" for a second before I realized... :D
No Climbing Today!
Rain sucks, but broken holds suck even more. Remember, never climb on wet rock in Fontainebleau.
The sandstone becomes brittle, and pulling on it will ruin classic problems. Drying it doesn't help, because it's still wet and weak inside.
All you can do is wait for better conditions.