Setting the active linkshell now works.

FFXIVClassic World Server/Packets/Send/Subpackets/Groups/SetActiveLinkshellPacket.cs

@@ -0,0 +1,42 @@
+using FFXIVClassic.Common;
+using FFXIVClassic_World_Server.DataObjects.Group;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace FFXIVClassic_World_Server.Packets.Send.Subpackets.Groups
+{
+    class SetActiveLinkshellPacket
+    {
+      
+        public const ushort OPCODE = 0x018A;
+        public const uint PACKET_SIZE = 0x98;
+
+        public static SubPacket BuildPacket(uint sessionId, ulong groupId)
+        {
+            byte[] data = new byte[PACKET_SIZE - 0x20];
+
+            using (MemoryStream mem = new MemoryStream(data))
+            {
+                using (BinaryWriter binWriter = new BinaryWriter(mem))
+                {
+                    //Write the LS groupId
+                    binWriter.Write((UInt64)groupId);
+                    
+                    //Write the LS group type
+                    binWriter.Seek(0x40, SeekOrigin.Begin);
+                    binWriter.Write((UInt32)Group.CompanyGroup);
+
+                    //Seems to be a index but can only set one active so /shrug
+                    binWriter.Seek(0x60, SeekOrigin.Begin);
+                    binWriter.Write((UInt32)(groupId == 0 ? 0 : 1));
+                }
+            }
+
+            return new SubPacket(OPCODE, sessionId, sessionId, data);
+        }
+    }
+}