Can you share one of the saves here? I'll check if I can see and load it.

Sublustris wrote:

Can you share one of the saves here? I'll check if I can see and load it.

Yes, i do, tks!! 01.sav

It appears your saves are corrupted, this is what I've got in diagnostic log

20:46:58:246GameplaySTACKAn exception occurred while retrieving game save descriptor C:\Users\Sublustris\Documents\Endless Space 2\Save Files\Cloud\01-1.sav

20:46:58:247GameplaySTACKWrong local header signature @0

20:47:03:823PrismSTACKError: {"error message":"An exception occurred while retrieving game save descriptor C:\\Users\\Sublustris\\Documents\\Endless Space 2\\Save Files\\Cloud\\01-1.sav","callstack":" at RetrieveGameSaveDescriptor in :line 0\n at MoveNext in :line 0\n at MoveNext in :line 0\n at AddEnumerable in :line 0\n at AddRange in :line 0\n at Refresh in :line 0\n at Update in :line 0\n at Update in :line 0\n","turn":0,"gameID":null,"eventID":"5.19.01","eventName":"Error","steamID":"76561197995690653","gamecode":"392110","sessionID":"c056977f335a4317b4966913e8d6cf48","eventTimestampClient":"2021-07-07T20:46:55.465"}

Were you able to still load them on old machine? Could it be you used mods or custom factions?