Thanks for reporting this problem. I have fixed mcscf_ohvmo.F and mcscf_aux.F in a number of places where it was implicitly (and incorrectly) assumed that nclosed is always greater than 0. The fixes have gone into the current development version. If you send me and email (hubertus dot vandam at pnnl dot gov) I can send you instructions as to how to get an up-to-date version of the code.