I am using minecraft/hamachi and lan world (modded survival)

[X_Calibur]

When me and my friend play he tries to join my world and it worked for a while but he tried and now it days a fetal error has occurred and it doesn't let him join my world it started happening because he used a tinkers long sword he used the double jump but after that he was able o join for a sec and i killed him to see if it was the long sword but it wasent the case so he exited his hamachi and started it up again and it worked but then the next day he tried to join and a fetal error has occurred so i dont know

[X_Calibur]

ugggggh idk what log even post tomorrow so we can try again so i can find the log