Requirement: You need the savegame files on your PC.
I installed ACC Origins after a few years to finish it but, Ubisoft Connect gave me the "Failed to synchronize cloud saves" Error, so I hade no savegames after starting the game. But I made a backup of my savegames years before a Windows 10 install. I copied the savegame files into the "C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\savegames\UBISOFT_ID_HERE\3539" folder but it wasn't working.... I tried every solution that Ubisoft had in his sleeve but nothing worked (a typically ubisoft).
But I had an idea. I read about a ACSaveTool so I tried it and it worked.
Start Ubisoft ConnectUntick "Enable cloud save synchronization for supported games"
Backup all save files in folder 3539 (ACC Origins)Start the ACSaveTool"Open" your old savegame files with this toolChoose your GameTick on
Detect (Decryption ID is greyed out)Enter your Ubisoft ID in
Encryption ID ("C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\savegames\
UBISOFT_ID_HERE\3539")ConvertCopy converted files into the savegame folder ("C:\Program Files (x86)\Ubisoft\Ubisoft Game Launcher\savegames\UBISOFT_ID_HERE\3539")Start the gameYou can tick "Enable cloud save synchronization for supported games"