Immediate success at platoon/company/battalion level coupled with ultimate failure at corps/army level.
Why
Ludendorff violated his own concept by his tendency to use strategic reserves to reinforce against hardened resistance—hence, at the strategic level, he seduced himself into supporting failure not success.
Exhaustion of combat teams leading the assault.
Logistics too inflexible to support rapid/fluid penetration and deeper exploitation of breakthrough.
Communications too immobile to allow command to quickly identify and reinforce successful advances.
Elastic Zone Defense, when used, (as developed by the Germans and practiced by Pétain) that emphasizes artillery and flank attacks against penetrations when they stretch beyond their own artillery support.