I edit in Space exploration settings "Deep space conveyor speed" to 239. Game is restarted. I start new freeplay game and check deep space conveyor is fine with this speed.
Exit to main menu, load my main save (without sync mods and settings, so deep belt speed is changed) and got this in log:
Ok, I want to play, revert somehow:107.048 Loading map C:\Users\John Doe\AppData\Roaming\Factorio\saves\K2SE.zip: 174644721 bytes.
107.111 Loading level.dat: 592605972 bytes.
107.130 Info Scenario.cpp:198: Map version 1.1.41-0
120.575 Loading blueprint storage: Local timestamp 1633776279, Cloud timestamp 1633776278
120.641 Loading script.dat: 14702474 bytes.
124.180 Error AppManagerStates.cpp ...Data/Roaming/Factorio/temp/currently-playing/control.lua:2: module sandbox not found; no such file C:/Users/John Doe/AppData/Roaming/Factorio/temp/currently-playing/sandbox.lua no such file C:/Users/John Doe/AppData/Roaming/Factorio/temp/currently-playing/sandbox.lua no such file __core__/lualib/sandbox.lua
[C]: in function 'require'
...Data/Roaming/Factorio/temp/currently-playing/control.lua:2: in main chunk
Load with sync mods settings: same. (In mod settings deep speed revert to 90)
Reboot game: same.
Unload all mods, restart, synced load main save: same.
Check local file consistency through steam: all ok, but same.
Same: I may start new game but I do not able load any save file