Amazingly its not listed here:
Old Guns is a Minutemen main quest and achievement/trophy in Fallout 4. Approximately three days after the Minutemen retake the Castle, Ronnie Shaw will arrive there seeking out the Sole Survivor. Preston Garvey will inform the Sole Survivor that the Castle has been trying to reach them via...
fallout.fandom.com
My gut tells me its not a bug. I would guess a mod is causing this.
I would check the mod page for any minuteman mods you have and see if they make changes to this quest.
You could load your entire modlist in xEdit. Then look for the artillery constructable object to see if any mods are editing the conditions.
Many thanks, I tried to disable WAT e MiM, but nothing change. Maybe it's somethig else? I diminuited my mod list, but I see that I have too much actives.
1) Unofficial FO4 Patch;
2) Spring cleaning;
3) Ethreon master plan;
4) Snap'n build;
5) Pool table storage racks;
6) Homemaker;
7) Unlock settlements object;
8) True storms;
9) Integrated Commonwealth;
10) HUD framework;
11) You and what army;
12) Canary savefile monitor;
13) Workshop framework;
14) SS2 (later I'll activate Chapter 2 and many add-on);
15) Truestorms Far Harbor;
16) Truestorms earlier sunset;
17) Truestorms earlier sunset Far Harbor;
18) Repaired roof Sanctuary;
19) Old Time Religion;
20) FCOM;
21) Commonwealth on air;
22) No object limit;
23) Repair Sanctuary;
24) Minutemen General Uniform;
25) Generator fusebox;
26) Goodneighbour expanded;
27) Increased build;
28) Armor tables;
29) Dinomore;
30) Weapons display;
31) Better settlers;
32) Better settlers faceonly;
33) Cartman warehouse;
34) Militarized Minutemen;
35) Militarised Minutemen uniforms patches and insignia addon;
36) We are the Minutemen;
37) WATM - MiM patch compatibilities;
38) Eli armor compendium;
39) JCW builder;
40) Workshop rearranged;
41) OCD decorator;
42) OCD dispender;
43) Settle object expand pack;
44) Settle object expand pack light shadow disable;
45) Bunker 1 linked containers;
46) Guard towers;
47) Snappy House;
48) Settlement menù management;
49) Minutemen armor;
50) PAC (I don't remember wby type of mod is);
51) Sanctuary Hills roofs and walls rix;
52) More where that came from Diamond City;
53) FO4 NPC travels;
54) norespawn homeplate;
55) dinoshelf;
56) Amelia and Dan at bunker Hill;
57) Minutemen armory;
58) Minutemen morale;
59) Diamond City enhanced security;
60) Everyone's best friend;
61) Easy hacking;
62) Orphans;
63) Children of Bunker Hill;
64) Children of Goodneighboor;
65) Provisioner uniform;
66) Immersive Lexington;
67) Soldier starter;
68) Enclave plasma;
69) longer food buffs;
70) Better Drumlin Dinner;
71) Concord Hideout;
72) Minutemen radiant squads;
73) The Sanctuary Bridge;
74) creative clutter;
75) Wattz lasergun;
76) Recruitable settlers;
77) Recruitable settlers Far Harbor;
78) Minutemen Sentinel;
79) Diamond City expansion;
80) Diamond City expansion exo patch;
81) Diamond City expansion pre-vis.
