One of my friends cant play multiplayer co-op, please help!

[💀 Soul King 💀]

So I am hosting a local coop with my friends using Zerotier, it works perfectly fine with me and all my friends except one, We have Steam version and one of my friends keeps getting this error :
"the server has closed the connection"

We tried everything, from changing his Zeroteir IP, reinstalling the game, verifying game files on steam, we are playing on version 1.5.5 BETA, please note that we are playing with one legit copy which is my steam copy, my friends plan to get the game on Steam in the near future but they can't right now because of financial issues, please help us enjoy the game together until then, thank you in advance.
nothing worked, this is the error he gets before his game crashes:
https://drive.google.com/file/d/1khrSBzb5iJYGirKytY-vwmmhKV8UAa6H/view?usp=sharing

ERROR MESSAGE LOG FROM MY FRIEND'S SIDE:



Message: Error on new day:

---------------

Exception of type 'StardewValley.AbortNetSynchronizerException' was thrown.

at StardewValley.NetSynchronizer.barrier(String name) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Network\NewDaySynchronizer.cs:line 57

at StardewValley.Game1._newDayAfterFade()+MoveNext() in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 9219

at StardewValley.Game1.<>c.<newDayAfterFade>b__713_2() in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 8589

at System.Threading.Tasks.Task.InnerInvoke()

at System.Threading.Tasks.Task.<>c.<.cctor>b__277_0(Object obj)

at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)

--- End of stack trace from previous location ---

at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state)

at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)

---------------


InnerException:

Stack Trace: at StardewValley.Game1._update(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 4114

at StardewValley.Game1.Update(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\Game1.cs:line 3934

at StardewValley.GameRunner.Update(GameTime gameTime) in C:\GitlabRunner\builds\Gq5qA5P4\0\ConcernedApe\stardewvalley\Farmer\Farmer\LocalMultiplayer.cs:line 1066

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 163


Game Version: 1.5.5

SDK Helper: SteamHelper

Game Language: en

GPU: GeForce 820M/PCIe/SSE2

OS: Win32NT Microsoft Windows NT 10.0.19043.0

Multiplayer (Client)

In-game Date: summer 27 Y2 Time of Day: 2540

Game Location: Cabinc4700717-c3ad-464b-8b62-14ce6a4739bf