diff --git a/TBF/Properties/AssemblyInfo.cs b/TBF/Properties/AssemblyInfo.cs
index c613c261c..b04bfa3cb 100644
--- a/TBF/Properties/AssemblyInfo.cs
+++ b/TBF/Properties/AssemblyInfo.cs
@@ -29,5 +29,5 @@ using System.Runtime.InteropServices;
 //      Build Number
 //      Revision
 //
-[assembly: AssemblyVersion("3.1.1601.0")]
-[assembly: AssemblyFileVersion("3.1.1601.0")]
+[assembly: AssemblyVersion("3.1.1602.0")]
+[assembly: AssemblyFileVersion("3.1.1602.0")]
diff --git a/TBF/Rig/Sequences/MainSeqUtils.cs b/TBF/Rig/Sequences/MainSeqUtils.cs
index ef418a72c..f4155ce5f 100644
--- a/TBF/Rig/Sequences/MainSeqUtils.cs
+++ b/TBF/Rig/Sequences/MainSeqUtils.cs
@@ -493,9 +493,9 @@ namespace TBF.Rig.Sequences
                 }
 
                 /// Tank emptying valves states
-                bool draining1 = (StateMachine.DrainValve1 != null);
-                bool draining2 = (StateMachine.DrainValve2 != null);
-                bool draining3 = (StateMachine.DrainValve3 != null);
+                bool draining1 = (StateMachine.DrainValve1 != null && StateMachine.Tank1 != null);
+                bool draining2 = (StateMachine.DrainValve2 != null && StateMachine.Tank2 != null);
+                bool draining3 = (StateMachine.DrainValve3 != null && StateMachine.Tank3 != null);
 
                 int drainingStartTime = StateMachine.Time;
 
@@ -517,9 +517,9 @@ namespace TBF.Rig.Sequences
                         .EnterState();
                     while (StateMachine.WaitRunDevsRunOps().Contains(Event.Busy)) { }
 
-                    if (draining1 && StateMachine.Tank1.IsEmpty()) draining1 = false;
-                    if (draining2 && StateMachine.Tank2.IsEmpty()) draining2 = false;
-                    if (draining3 && StateMachine.Tank3.IsEmpty()) draining3 = false;
+                    if (draining1 && StateMachine.Tank1 != null && StateMachine.Tank1.IsEmpty()) draining1 = false;
+                    if (draining2 && StateMachine.Tank2 != null && StateMachine.Tank2.IsEmpty()) draining2 = false;
+                    if (draining3 && StateMachine.Tank3 != null && StateMachine.Tank3.IsEmpty()) draining3 = false;
                 }
 
                 /// Close all drain valves