Waste incineration enables you to burn obsolete stuff to generate energy. Different types of ash remaining in this process can be smelted to regain some of the metals.
The error message indicates that there's a mod conflict betweeen advanced waste management and "additional turrets". Which additional turret mod do you use? I tried the mod from sore68 but had no issues.
For further investigations I would need your "factorio-current.log" (in %AppData%/Factorio) and your "mod-list.json" (in %AppData%/Factorio/mods). You can send me these files via PM in the forum.
