I am happy to report that the Linux build for 0.11.0b runs normally.  Saving and loading is fast.  While there were 3200 lines of errors in godot.log after one hour of gaming, that's better than 1.5 million.

SCRIPT ERROR: Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'.

   at: process_effects_expand (res://src/character/ch_dyn_stats.gd:162) - Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'.

and

SCRIPT ERROR: Invalid get index 'sid3840352285' (on base: 'Dictionary').

   at: clone_stack (res://src/core/effects_pool.gd:84) - Invalid get index 'sid3840352285' (on base: 'Dictionary').

and

SCRIPT ERROR: Invalid call. Nonexistent function 'keys' in base 'Nil'.

   at: has_status (res://src/character/ch_dyn_stats.gd:200) - Invalid call. Nonexistent function 'keys' in base 'Nil'.

and suchlike are repeated many times, but they are not breaking the game as far as I can tell.

Cheers.

Would be nice if you could find out which action exactly leads to the error 

I'm looking into it.  For example, I can tell you that I had four characters total, all in the mansion, one upgrading to the first level of Tailoring module, one fishing, one smithing an axe with a hunting knife queued, and one cooking meat soups with a single unit of bread queued.  I advance time, and this happens:

SCRIPT ERROR: Invalid get index 'id' (on base: 'Nil').

   at: build_location_group (res://gui_modules/Exploration/Scripts/ExplorationModule.gd:530) - Invalid get index 'id' (on base: 'Nil').

Ok, I reload, advance time again, and the same thing happens.  During that turn, the Tailor upgrade was not completed.  The fishing continued.  The axe was made, but the hunting knife was not.  The cook finished meat soups and the bread and was left with nothing to do.  

It says 'Exploration module', but I'm not out exploring, so maybe it's the cook running out of work?  I reload again, same thing happens, three times I reload, same error.

But then I exit the game, reload to the same save, advance time, and there is no error.  That isn't the only time I've 'lost' an error that way.

I will keep looking, but I can say for certain that some errors do not appear in the log from a fresh game start that would if you had been playing through.

Eh, now the same error showed up when I went out to Threat - Wild Wolves.  But only the second time I went out there, because I reloaded trying to figure out what

effect eid3939004809 is removed as applied to no one

is exactly.  So I have no idea what

SCRIPT ERROR: Invalid get index 'id' (on base: 'Nil').

   at: build_location_group (res://gui_modules/Exploration/Scripts/ExplorationModule.gd:530) - Invalid get index 'id' (on base: 'Nil').

is at all.  I can't make a link to what I am doing in game when it shows up.

Question - Are the .sav and .dat files proprietary to the program/system build or are they universal? Can Jotok (linux system) share his saved game with Maverik so that Maverik can see his game state? I know the errors shouldn't migrate (if they do then that is another clue), but it should give Maverik a better idea of what the game is trying to do when it is giving Jotok those errors.

I have a few errors nailed down, and one not.  In 0.11.0b:

Daisy sent for maid training causes:

SCRIPT ERROR: Invalid call. Nonexistent function 'set_combat_position' in base 'Reference (CharacterClass.gd)'.

          at: make_unavaliable (res://src/character/ch_leveling.gd:362)

While I was in The Black Cavern, which was a location I had been to, left, and then came back to.  I had been through two rooms I think before this happened.

SCRIPT ERROR: Invalid get index 'L32L1  12' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  13' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  14' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  17' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  18' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  19' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  22' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  23' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  24' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  12' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  13' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  14' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  17' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  18' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  19' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  22' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  23' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

SCRIPT ERROR: Invalid get index 'L32L1  24' (on base: 'Dictionary').

          at: update (res://gui_modules/Exploration/Scripts/room.gd:24)

During battles with Liches:

ERROR IN AI TEMPLATE

Went into inventory after a battle and put a looted Magic Tome in a character's hand:

SCRIPT ERROR: Invalid get index 'is_stored' (on base: 'Nil').

          at: eff_stack.clear_nonstored_effs (res://src/classes/eff_stack.gd:134)

And the big one, which I can't assign a reason for.  At the mansion, advance time and:

SCRIPT ERROR: Invalid get index 'sid1630480949' (on base: 'Dictionary').

          at: clone_stack (res://src/core/effects_pool.gd:84)

SCRIPT ERROR: Invalid get index 'sid2562762970' (on base: 'Dictionary').

          at: clone_stack (res://src/core/effects_pool.gd:84)

SCRIPT ERROR: Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'.

          at: process_effects_expand (res://src/character/ch_dyn_stats.gd:162)

SCRIPT ERROR: Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'.

          at: generate_data (res://src/character/ch_dyn_stats.gd:145)

SCRIPT ERROR: Invalid call. Nonexistent function 'clear_nonstored_effs' in base 'Nil'.

          at: clear_nonstored_effs (res://src/character/ch_dyn_stats.gd:108)

shows up.  47 times in a row.  All at once out of the blue.

SCRIPT ERROR: Invalid call. Nonexistent function 'get_active_effects' in base 'Nil'.

          at: has_status (res://src/character/ch_dyn_stats.gd:200)

showed up once between the third and fourth lines on the 27th iteration, and then four times in a row between the fourth and fifth lines on the 31st iteration, then again between the fourth and fifth lines on the 39th iteration.  I hope that is clear enough to spare you and itch from me simply posting all those lines.

I have no idea what causes that.  I have seen it in the mansion, I have seen it while travelling, and I have seen it while in a dungeon. I can't tie it to a specific action.  I also can't tell if anything is actually broken in the user experience after it happens.

Good luck :/