Why won't my chocolate set properly?

Chocolate that stays soft or sticky after setting usually has a tempering issue — the cocoa butter didn't crystallize into stable Type V crystals. This can happen from overheating, insufficient cooling, or inadequate agitation during tempering. Re-melt the chocolate and temper again from scratch. Other causes: compound chocolate (no tempering needed but may be too thin) or added ingredients (cream, oil) that broke the chocolate's structure. Check your thermometer accuracy with an ice water test.