I have the exact same issue as you. I have been playing on iPad and recently moved to PC (not playing with any mods). I have tried to transfer my mobile save to the PC but it crashes on the loading screen when I select the game. The error message is:
Message: There is an error in XML document (1, 1092871).
InnerException: System.ArgumentException: Requested value 'Mill' was not found.
at System.Enum.TryParseByName(RuntimeType enumType, String originalValueString, ReadOnlySpan`1 value, Boolean ignoreCase, Boolean throwOnFailure, UInt64& result)
at System.Enum.TryParseInt32Enum(RuntimeType enumType, String originalValueString, ReadOnlySpan`1 value, Int32 minInclusive, Int32 maxInclusive, Boolean ignoreCase, Boolean throwOnFailure, TypeCode type, Int32& result)
at System.Enum.TryParse(Type enumType, String value, Boolean ignoreCase, Boolean throwOnFailure, Object& result)
at Netcode.NetEnum`1.Add(String value) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Netcode\NetEnum.cs:line 63
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read20_Chest(Boolean isNullable, Boolean checkType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read105_Mill(Boolean isNullable, Boolean checkType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read110_Building(Boolean isNullable, Boolean checkType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read113_Farm(Boolean isNullable, Boolean checkType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read190_GameLocation(Boolean isNullable, Boolean checkType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read237_SaveGame(Boolean isNullable, Boolean checkType)
at Microsoft.Xml.Serialization.GeneratedAssembly.XmlSerializationReaderSaveGame.Read238_SaveGame()
Stack Trace: at StardewValley.SaveGame.getLoadEnumerator(String file)+MoveNext() in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\SaveGame.cs:line 1510
at StardewValley.Game1.UpdateTitleScreen(GameTime time) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 6307
at StardewValley.Game1._update(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 4906
at StardewValley.Game1.Update(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 3974
at StardewValley.GameRunner.Update(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\LocalMultiplayer.cs:line 1067
at Microsoft.Xna.Framework.Game.DoUpdate(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\MonoGame.Desktop\MonoGame.Framework\Game.cs:line 814
at Microsoft.Xna.Framework.Game.Tick() in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\MonoGame.Desktop\MonoGame.Framework\Game.cs:line 567
at Microsoft.Xna.Framework.SdlGamePlatform.RunLoop() in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\MonoGame.Desktop\MonoGame.Framework\Platform\SDL\SDLGamePlatform.cs:line 91
at Microsoft.Xna.Framework.Game.Run(GameRunBehavior runBehavior) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\MonoGame.Desktop\MonoGame.Framework\Game.cs:line 481
at StardewValley.Program.Main(String[] args) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Program.cs:line 175
Game Version: 1.5.6 Hotfix #3
SDK Helper: SteamHelper
Game Language: en
GPU: Intel(R) Iris(R) Xe Graphics
OS: Win32NT Microsoft Windows NT 10.0.22621.0
In-game Date: spring 0 Y1 Time of Day: 600
Game Location: null