Switching to a build before build 2023-11-04-0144 destroys the save

[Unrepentant-Atheist]

Describe the bug

If you have a save game and switch to build 2023-11-04-0144 to test, then switch back to former builds, kiss you save game good bye.

Edit: Maybe not really a "bug", since there's a lot of code change in this PR. Still reported. Close if irrelevant.

Steps To Reproduce

1. Have a save game
2. download and play build 2023-11-04-0144
3. Switch back to any other build before that
4. ???
5. Don't profit no more.

Screenshots

Versions and configuration

• OS: Windows
  • OS Version: 10.0.19045.3570 (22H2)
• Game Version: daddaec [64-bit]
• Graphics Version: Tiles
• LAPI Version: 1
• Game Language: English [en_US]
• Mods loaded: [ Bright Nights [bn], SpeedyDex [speedydex], Stats Through Kills [stats_through_kills], Stats Through Skills [StatsThroughSkills], Bionic Slots [cbm_slots], Elevated bridges [elevated_bridges], Cataclysm++ [Cata++], Aftershock [aftershock], PKs Rebalancing [PK_REBALANCE], Secronom [secronom], Secronom+ Lore Expansion [secronom_lore_expansion], C.R.I.T. Expansion [crt_expansion], Sierra Madre [sierra_madre], Bio-Synth Robot expansion [gekkobots], Nechronica Redux [Nechronica_Redux], Magiclysm [magiclysm], Really Dark Skies [realdarkskies], Arcana and Magic Items [Arcana], Project: Pack Rat [Jake's_Squirrel_mod], Add Bandits Extended+ [GOV_BANDITS_KAI_R], NPC Increased Location Spawns Combined [npc_increased_location_comb], More Bandits, Testing version [More_Bandits], More Dangerous Encounters [More_Dangerous_Encounters], Vampiric Stuff [vamp_stuff], Vampiric Stuff + Arcana Mod Extension [vamp_stuff+arcana], Magiclysm Revamp and Additions [magicrevamp], Miscellaneous Magiclysm Expansions [demon_spider_a], Urban Development [Urban_Development], Morlock Village [morlock_village], Arcana/Cata++ Patchmod [Arcana_Cata++_Patch], Arcana/Aftershock Patchmod [Arcana_aftershock_Patch], Arcana/C.R.I.T. Patchmod [Arcana_Crit_Patch], Arcana/Magiclysm Patchmod [Arcana_Magiclysm_Patch], Really Dark Skies plus Arcana [realdarkskies_Arcana_patchmod], Really Dark Skies plus Cataclysm++ [realdarkskies_CATA_patchmod], Really Dark Skies plus Aftershock [realdarkskies_aftershock_patchmod], Really Dark Skies plus PKs Rebalancing [realdarkskies_PK_REBALANCE_patchmod], Really Dark Skies plus Secronom [realdarkskies_secronom_patchmod], Really Dark Skies plus C.R.I.T. [realdarkskies_CRIT_patchmod], Really Dark Skies plus Bio-Synth Robot Expansion [realdarkskies_gekkobots_patchmod], Really Dark Skies plus magiclysm [realdarkskies_magiclysm_patchmod], Really Dark Skies plus Morlock Village [realdarkskies_morlock_village_patchmod], Even More Mutations [even_more_mutations], Mutant NPCs [mutant_npcs], Psychiclysm [psychiclysm], Modular Turrets with No Blacklist [modular_turrets_no_blacklist], Salvaged Robots [Salvaged_Robots], Bug's life [Bug's life], Mutant Animals [mutant_animals], Mutant Insects [mutant_insects], DinoMod [DinoMod], Arcana/DinoMod Patchmod [Arcana_Dinomod_Patch], Really Dark Skies plus DinoMod [realdarkskies_Dino_patchmod], Mythical Martial Arts [MMA], Mythical Martial Arts - Mods Extension [MMA_Mods_Extension], Wield Wild Weapons [WIELD_WILD_WEAPONS], Tankmod: Revived [Tankmod_Revived], Valik's Machine Shop 1.1 [valikengines], Thog's Vehicles [Thogs_Vehicles], Really Dark Skies plus Thog's Vehicles [realdarkskies_Thogs_Vehicles_patchmod], Thog's Things [Thogs_Things], CDDA Variety Pack [ks_variety_pack], Hydroponics [hydroponics], Wandering Masters [wandering_masters], Expanded Archery [ExArch], MST Extra [MST_Extra], Makeshift Items Mod [makeshift], Bionic Space Expander [Bionic_Space_Expander], Bionics Systems Recipes [bio_recipes], Caches [P_Caches], Dorf Life [Dorf_Life], Randomized Mall [randomized_mall], Tekitou Map Commercial Overhaul [tekitoumap], Beta National Guard Camp [national_guard_camp], Nuclear Power Plant [NPP], Mug NPCs [mug_NPCs], NPC Recruitment Options [recruitment_options], Necropolis Actually Findable [necro_find], Lones Atomic additions [lones atomic additions], Lones CBM slot balance [lones_CBM_slot balance], Lones Flesh Raptor [flesh raptors], Lones Translocator Gates [translocator_gates], Lones Tweaks [lonestweaks], Chorus's Arcana Addon [Chorus Arcana Addon], Chorus's Gear [Chorus_Weapons], Chorus's CBMs [Chorus CBMs], Chorus's Martial Arts [Chorus_MA], Idzibear's Additions Testing Ground [Idzibear_Additions_test] ]

Additional context

Save: https://nowtransfer.de/bc5556958c65

Debug.log

04:22:54.944 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\cata_utility.cpp:534 [read_from_file] Failed to read from "D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.0.2": Json error: D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.0.2:32:9.295: tried to start object, but found '0', not '{'

ck":0},{"typeid":"textbook_anarch","bday":1800000,"owner":"solo_Nita Trinh","last_rot_check":0},{"typeid":"shovel","bday":1800000,"owner":"solo_Nita Trinh","last_rot_check":0}],"last_target_pos":null,"destination_point":null,"ammo_location":0
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  ,"camps":[],"marked_for_death":false,"dead":false,"patience":0,"myclass":"NC_NPC_MUTANT_ALPHA","known_to_u":false,"personality":{"aggression":-3,"bravery":7,"collector":3,"altruism":4},"submap_coords":[4,778],"last_player_seen_pos":null,"go

04:23:08.964 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\cata_utility.cpp:534 [read_from_file] Failed to read from "D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.0.1": Json error: D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.0.1:32:8.814: tried to start object, but found '0', not '{'

re_hardened_fletched","charges":13,"owner":"no_faction","last_rot_check":0},{"typeid":"arrow_heavy_fire_hardened_fletched","charges":7,"owner":"no_faction","last_rot_check":0}],"last_target_pos":null,"destination_point":null,"ammo_location":0
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  ,"camps":[],"marked_for_death":false,"dead":false,"patience":0,"myclass":"npk_scav_friendly_npc","known_to_u":false,"personality":{"aggression":-10,"bravery":6,"collector":1,"altruism":-5},"submap_coords":[172,588],"last_player_seen_pos":nu

04:23:09.085 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\cata_utility.cpp:534 [read_from_file] Failed to read from "D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.-1.1": Json error: D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.-1.1:32:10.137: tried to start object, but found '0', not '{'

"typeid":"beer","charges":1,"bday":702000,"active":true,"last_rot_check":0}]}},{"typeid":"manual_knives","bday":702000,"owner":"solo_Nannie 'Thorn' Koenig","last_rot_check":0}],"last_target_pos":null,"destination_point":null,"ammo_location":0
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  ,"camps":[],"marked_for_death":false,"dead":false,"patience":0,"myclass":"NC_NPC_MUTANT_MEDICAL","known_to_u":false,"personality":{"aggression":-3,"bravery":1,"collector":10,"altruism":-1},"submap_coords":[-74,504],"last_player_seen_pos":nu

04:23:09.172 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\cata_utility.cpp:534 [read_from_file] Failed to read from "D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.-1.2": Json error: D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.-1.2:32:9.721: tried to start object, but found '0', not '{'

3200,"owner":"solo_Tresa Landrum","last_rot_check":0},{"typeid":"smart_phone","charges":160,"bday":1303200,"owner":"solo_Tresa Landrum","last_rot_check":0,"curammo":"battery"}],"last_target_pos":null,"destination_point":null,"ammo_location":0
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  ,"camps":[],"marked_for_death":false,"dead":false,"patience":0,"myclass":"NC_NPC_MUTANT_LIZARD","known_to_u":false,"personality":{"aggression":-2,"bravery":-2,"collector":8,"altruism":-3},"submap_coords":[-122,758],"last_player_seen_pos":nu

04:23:10.047 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\cata_utility.cpp:534 [read_from_file] Failed to read from "D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.1.1": Json error: D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.1.1:32:9.696: tried to start object, but found '0', not '{'

{"typeid":"weed","charges":5,"bday":4158000,"owner":"solo_Davis Wang","last_rot_check":0},{"typeid":"power_supply","bday":4158000,"owner":"solo_Davis Wang","last_rot_check":0}],"last_target_pos":null,"destination_point":null,"ammo_location":0
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  ,"camps":[],"marked_for_death":false,"dead":false,"patience":0,"myclass":"NC_NPC_MUTANT_FELINE","known_to_u":false,"personality":{"aggression":2,"bravery":6,"collector":10,"altruism":-2},"submap_coords":[378,616],"last_player_seen_pos":null

04:23:10.135 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\cata_utility.cpp:534 [read_from_file] Failed to read from "D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.1.2": Json error: D:/CDDA/bn/userdata/save/Randomville_morenpc_ChorusLones-Test/o.1.2:32:10.197: tried to start object, but found '0', not '{'

"charges":1,"bday":4298400,"owner":"solo_Jim Rutledge","last_rot_check":0},{"typeid":"medical_gauze","charges":1,"bday":4298400,"owner":"solo_Jim Rutledge","last_rot_check":0}],"last_target_pos":null,"destination_point":null,"ammo_location":0
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  ,"camps":[],"marked_for_death":false,"dead":false,"patience":0,"myclass":"NC_NPC_MUTANT_BIRD","known_to_u":false,"personality":{"aggression":9,"bravery":-2,"collector":10,"altruism":2},"submap_coords":[524,846],"last_player_seen_pos":null,"

04:23:11.392 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\savegame.cpp:259 [unserialize] Bad save json
Json error: <unknown source file>:24:6.733: tried to start object, but found '7', not '{'

vity": { "type": "ACT_NULL" }, "stashed_outbounds_backlog": { "type": "ACT_NULL" }, "backlog": [ { "type": "ACT_READ", "actor": null, "moves_left": 5220, "index": 1, "position": 1, "coords": [  ], "coord_set": [  ], "name": "", "targets": [ 7
                                                                                                                                                                                                                                                 ^
                                                                                                                                                                                                                                                  297441966126530561 ], "placement": [ -2147483648, -2147483648, -2147483648 ], "values": [  ], "str_values": [  ], "auto_resume": false, "monsters": [  ] } ], "activity_vehicle_part_index": -1, "weapon": { "typeid": "katar", "bday": 2402481,

04:23:13.520 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\map.cpp:1128 [board_vehicle] map::board_vehicle: passenger (<null>) is already there
04:23:14.385 ERROR DEBUGMSG : D:\a\Cataclysm-BN\Cataclysm-BN\src\map.cpp:1150 [unboard_vehicle] map::unboard_vehicle: passenger not found

[AniDemi]

We do put in measures for some backwards compatibility, but I don't think we have forward compatibility. If I'm right then this is not a bug, you're just not supposed to load a save that has been saved on a new build onto an older build.

[scarf005]

if the issue is indeed caused by forward compatibility, then I'm afraid we cannot help more. the game is fragile and not designed for forward compatibility. if the issue isn't related to forward compatibility, please re-open the issue.