diff --git a/core/resources/l10n/messages.properties b/core/resources/l10n/messages.properties
index 1b94f637b..87a2d18d9 100644
--- a/core/resources/l10n/messages.properties
+++ b/core/resources/l10n/messages.properties
@@ -563,6 +563,7 @@ SimuRunDlg.msg.Unabletosim = Unable to simulate:
 SimuRunDlg.msg.errorOccurred = An error occurred during the simulation:
 
 BasicEventSimulationEngine.error.noMotorsDefined = No motors defined in the simulation.
+BasicEventSimulationEngine.error.cantCalculateStability = Can't calculate rocket stability.
 BasicEventSimulationEngine.error.earlyMotorBurnout = Motor burnout without liftoff.
 BasicEventSimulationEngine.error.noConfiguredIgnition = No motors configured to ignite at liftoff
 BasicEventSimulationEngine.error.noIgnition = No motors ignited.
@@ -1149,8 +1150,6 @@ NoseConeCfg.tab.General = General
 NoseConeCfg.tab.ttip.General = General properties
 NoseConeCfg.tab.Shoulder = Shoulder
 NoseConeCfg.tab.ttip.Shoulder = Shoulder properties
-NoseConeCfg.checkbox.Flip = Flip to tail cone
-NoseConeCfg.checkbox.Flip.ttip = Flips the nose cone direction to a tail cone.
 
 ! ParachuteConfig
 Parachute.Parachute = Parachute
@@ -1365,7 +1364,7 @@ TCMotorSelPan.lbl.Datapoints = Data points:
 TCMotorSelPan.lbl.Digest = Digest:
 TCMotorSelPan.title.Thrustcurve = Thrust curve:
 TCMotorSelPan.title.Thrust = Thrust
-TCMotorSelPan.delayBox.None = Plugged (none)
+TCMotorSelPan.delayBox.None = None
 TCMotorSelPan.noDescription = No description available.
 TCMotorSelPan.btn.checkAll = Select All
 TCMotorSelPan.btn.checkNone = Clear All
diff --git a/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java b/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java
index 513190b8b..e31fa4a98 100644
--- a/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java
+++ b/core/src/net/sf/openrocket/simulation/BasicEventSimulationEngine.java
@@ -7,7 +7,9 @@ import java.util.Deque;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import net.sf.openrocket.aerodynamics.FlightConditions;
 import net.sf.openrocket.aerodynamics.Warning;
+import net.sf.openrocket.aerodynamics.WarningSet;
 import net.sf.openrocket.l10n.Translator;
 import net.sf.openrocket.motor.IgnitionEvent;
 import net.sf.openrocket.motor.MotorConfiguration;
@@ -84,6 +86,13 @@ public class BasicEventSimulationEngine implements SimulationEngine {
 			throw new MotorIgnitionException(trans.get("BasicEventSimulationEngine.error.noMotorsDefined"));
 		}
 
+		// Can't calculate stability
+		if (currentStatus.getSimulationConditions().getAerodynamicCalculator()
+			.getCP(currentStatus.getConfiguration(),
+				   new FlightConditions(currentStatus.getConfiguration()),
+				   new WarningSet()).weight < MathUtil.EPSILON)
+			throw new SimulationException(trans.get("BasicEventSimulationEngine.error.cantCalculateStability"));
+
 		// Problems that let us simulate, but result is likely bad
 			
 		// No recovery device