Revert "Remove CM_Exception_Invalid from front-end."
Revert "Remove CM_Exception_Invalid from front-end."

This reverts commit 585e00213c5b85077eaedf153b53c2816e552cf1.

fauvel/CM,vogdb/cm,njam/CM,njam/CM,alexispeter/CM,cargomedia/CM,tomaszdurka/CM,alexispeter/CM,alexispeter/CM,zazabe/cm,cargomedia/CM,zazabe/cm,zazabe/cm,vogdb/cm,fauvel/CM,tomaszdurka/CM,njam/CM,vogdb/cm,vogdb/cm,fauvel/CM,tomaszdurka/CM,njam/CM,fauvel/CM,tomaszdurka/CM,alexispeter/CM,tomaszdurka/CM,njam/CM,fauvel/CM,zazabe/cm,cargomedia/CM,cargomedia/CM,vogdb/cm