Phosphatase with broad specificity; it can dephosphorylate fructose 1,6-bisphosphate, and both D and L isomers of inositol-1-phosphate (I-1-P). beta-D-fructose 1,6-bisphosphate + H2O = beta-D-fructose 6-phosphate + phosphate a myo-inositol phosphate + H2O = myo-inositol + phosphate Belongs to the inositol monophosphatase superfamily. FBPase class 4 family.