Defend

Help defend (settlement) are eleven Minutemen radiant quests in Fallout 4, varying in the group attacking the settlement.

Quick walkthrough
While playing you are notified via on screen text that a settlement needs your help defending it. On arrival you find it under attack, after a successful defense a settler will thank you and initiate a short conversation.

Detailed walkthrough
Your settlement can come under attack from one of several different groups: Super Mutants, Ghouls, Synths, Raiders, and Gunners. Simply killing them is all you need to do.

Bugs

 * Sometimes the quest objective might mark itself as completed before all enemies are killed.
 * Sometimes the quest doesn't complete.
 * Search inside and outside of the settlement for enemies that have not been killed and kill them.
 * Open the console. Target a dead enemy (by clicking on their corpse). Enter the command . Exit console. Kill the resurrected enemy. This will help in case the kill-counter is missing a kill.
 * If on arrival you find your settlers have killed a synth infiltrator you may also find there is no attack incoming. Open the console, and enter the command . The quest will complete.
 * When defending a settlement against an invasion of synths, the quest may become stuck and uncompletable if the first synth is killed before more can spawn.
 * Loading a save before killing the first synth will unstuck the quest.
 * Use console command to list all currently active quests, and find the appropriate quest ID, such as, and then use  to complete the quest.
 * After completing one of these quests, some settlers may get stuck in the "thank you" mode, i.e. constantly thanking you when you try to talk to them, locking out all other options such as trading and bartering.
 * This can be fixed by talking to a settler or shop-owner from another settlement.