How to Get the Rusty Key in Stardew Valley Expanded 1.15.11

How to Get the Rusty Key in SVE

Stardew Valley Expanded 1.15.11 moves the Rusty Key from Gunther to Marlon. Complete the Adventurer's Guild initiation, view Marlon's guild cutscene after more than ten in-game days have been played, then satisfy either the friendship route or the Year 2 mine route before entering the Adventurer Summit.

Exact unlock requirements

First, earn the guildMember flag by completing the guild's Initiation quest. Event 1000034 can then play inside the Adventurer's Guild once DaysPlayed > 10. The Rusty Key event 1090501 can trigger after that through either of these routes:

Route	Requirements
Friendship route	Reach 1,250 friendship points with Marlon, equal to 5 hearts. There is no year, weather, season or mine-bottom requirement on this route.
Mine route	Be in Year 2 or later and have reached the bottom of the regular Mines, floor 120. Five hearts with Marlon are not required.

Where and when the event starts

Complete the guild initiation, play event 1000034, and satisfy one of the two routes above.
Enter Adventurer Summit, the outdoor area beside the Adventurer's Guild.
Do this on a normal day. SVE excludes the Egg Festival, Stardew Valley Fair, Spirit's Eve and Feast of the Winter Star.
The event itself has no time, season or weather precondition. Marlon takes you to the Sewer and the event command directly awards the Rusty Key.

Rusty Key used to open the Sewer in Stardew Valley Expanded

What does not unlock the SVE key

Sixty Museum donations: SVE removes vanilla farm event 66, which normally gives the key. Gunther's replacement thank-you event does not award it.
The winter Shadow Guy: that sequence gives the Magnifying Glass, not the Rusty Key.
Rain: rainy weather belongs to a separate Marlon heart event and is not a sewer-key condition.
Mine floor 120 in Year 1: it does not satisfy the alternate route until Year 2. The five-heart route is the Year 1 option.

If the event still does not trigger

Confirm the SMAPI log shows SVE 1.15.11 and all required components loading successfully.
Make sure event 1000034 has played and event 1090501 has not already been seen.
For the friendship route, verify Marlon is at five full hearts; four hearts plus partial progress is below 1,250 points.
For the mine route, verify the save is in Year 2+ and the regular Mines, not Skull Cavern, has been cleared through floor 120.
Leave Adventurer Summit and re-enter it on a non-festival day after all conditions are true.

Version: Stardew Valley Expanded 1.15.11.