That's terrible news. I've been there twice in the last five years, including one visit where they had a Luftwaffe fly-by.
A wonderful museum, with nearly every aircraft flyable, as evidenced by the drip-trays under the engines. The only non-flyable exhibits I saw were the V1, V2 and Me 163 Komet, which was understandable.
During my last visit, they were re-building a Stuka.