I had problems with blueprints, a restart solved it.
Edited:
You need to update to 1.1.2 sleepy
Same error on 1.1.2
Failed to invoke Method ServerManagement:ClientFirstReady with 1 parameters: Sender: Player Client (3), timestamp: 3809.52
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object
at Magma.Player.get_SteamID () [0x00000] in <filename unknown>:0
at Magma.Player.Hooks_OnPlayerSpawned (Magma.Player player, Magma.Events.SpawnEvent se) [0x00000] in <filename unknown>:0
at (wrapper delegate-invoke) Magma.Hooks/PlayerSpawnHandlerDelegate:invoke_void__this___Pla yer_SpawnEvent (Magma.Player,Magma.Events.SpawnEvent)
at (wrapper delegate-invoke) Magma.Hooks/PlayerSpawnHandlerDelegate:invoke_void__this___Pla yer_SpawnEvent (Magma.Player,Magma.Events.SpawnEvent)
at (wrapper delegate-invoke) Magma.Hooks/PlayerSpawnHandlerDelegate:invoke_void__this___Pla yer_SpawnEvent (Magma.Player,Magma.Events.SpawnEvent)
at Magma.Hooks.PlayerSpawned (.PlayerClient pc, Vector3 pos, Boolean camp) [0x00000] in <filename unknown>:0
at ServerManagement.SpawnPlayer (.PlayerClient playerFor, Boolean useCamp, RustProto.Avatar avatar) [0x00000] in <filename unknown>:0
at NetUser.InitializeClientToServer () [0x00000] in <filename unknown>:0
at ServerManagement.ConnectUserToGame (.NetUser user) [0x00000] in <filename unknown>:0
at ServerManagement.ClientFirstReady (uLink.NetworkMessageInfo info) [0x00000] in <filename unknown>:0
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
--- End of inner exception stack trace ---
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
at #=qaL2AMBCaBLCj4lGSCwjcBVYUs_5vzeQVgu44HVklVYQ=.#= qG_E6hqIvz6NLWQQCT2N5IA== (System.Object #=qHU1X5mvYu3s1KCG5AbpxtA==, System.Object[] #=qkZ6vhdfn7DFsLIYEdsMCpg==) [0x00000] in <filename unknown>:0
Failed to invoke Method Inventory:IACT with 3 parameters: 4, 4, Sender: Player Client (3), timestamp: 4136.934
System.Reflection.TargetInvocationException: Exception has been thrown by the target of an invocation. ---> System.NullReferenceException: Object reference not set to an instance of an object
at Magma.Hooks.BlueprintUse (IBlueprintItem item, .BlueprintDataBlock bdb) [0x00000] in <filename unknown>:0
at BlueprintDataBlock.UseItem (IBlueprintItem item) [0x00000] in <filename unknown>:0
at BlueprintDataBlock.ExecuteMenuOption (MenuItem option, IInventoryItem item) [0x00000] in <filename unknown>:0
at InventoryItem`1[DB].OnMenuOption (MenuItem option) [0x00000] in <filename unknown>:0
at Inventory.IACT (Byte itemIndex, Byte action, uLink.NetworkMessageInfo info) [0x00000] in <filename unknown>:0
at (wrapper managed-to-native) System.Reflection.MonoMethod:InternalInvoke (object,object[],System.Exception&)
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
--- End of inner exception stack trace ---
at System.Reflection.MonoMethod.Invoke (System.Object obj, BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) [0x00000] in <filename unknown>:0
at System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) [0x00000] in <filename unknown>:0
at #=qaL2AMBCaBLCj4lGSCwjcBVYUs_5vzeQVgu44HVklVYQ=.#= qG_E6hqIvz6NLWQQCT2N5IA== (System.Object #=qHU1X5mvYu3s1KCG5AbpxtA==, System.Object[] #=qkZ6vhdfn7DFsLIYEdsMCpg==) [0x00000] in <filename unknown>:0