Greenskins

Greenskins (displayed as (Location Name): Greenskins) is a Minutemen radiant quest in Fallout 4.

Detailed walkthrough
After joining the Minutemen, this quest can be periodically obtained when talking to Preston Garvey or listening to Radio Freedom. The Sole Survivor is informed that an allied settlement is having trouble with some super mutants, and is asked to help the settlement deal with them. Alternatively, the quest may be obtained directly from a settler even if the Sole Survivor has not joined the Minutemen (this occurs more frequently at unowned settlements).

To proceed with the quest the Sole Survivor must travel to the settlement and talk to their leader, who will give the details: a large group of super mutants has been raiding the settlement and causing trouble. The settler will point the Sole Survivor to the mutants' hideout and ask that they be eliminated for the safety of the settlement.

To complete the objective, the Sole Survivor must travel to the mutant hideout and eliminate the marked super mutant. Unmarked enemies do not need to be killed to complete the quest. With the threat neutralized, the Sole Survivor can talk to the settler from before to receive thanks and a reward of ~100 caps, as well as ownership of the settlement (if it was not already owned). If the quest was given by Preston Garvey, the Sole Survivor must report back to him to turn in the quest; it will be completed immediately upon receiving the reward otherwise.

Bugs

 * The quest is radiant and prone to bugs. The most common bug affects super mutants: The quest will start as normal, but killing super mutants at the target location will not complete the objective, regardless of the counter updating or not. If the bug manifests, the quest arrow might not appear as well. Locations affected by this bug include Gwinnett Brewery, Breakheart Banks, Breakheart Banks, Faneuil Hall, and Scrap Palace. Somerville Place settlers appear to cause this bug to happen more often.
 * The bug can be fixed by using the console command, which will mark the super mutants as killed and activate completion dialogue with settlers.
 * The quest might not correctly activate the initial settler dialogue (eg. with Roger Warwick), making the quest impossible to complete.
 * The bug can fixed by using the console command, which will advance the quest without the need to go through dialogue.
 * In certain locations, NPCs might spawn in inaccessible locations (for instance, Roger Warwick at Warwick homestead might spawn inside the water cistern). This bug is shared with the other settlement quests.
 * This can be resolved by using the console command to teleport the NPC in question.
 * The Warwick homestead example can be resolved by building stairs into the cistern and a bell outside of it. Using the bell and waiting for an in-game hour (using the Wait option) will cause the NPCs to spawn near the bell.