Solved bug which was caused by obsoleting scouts when they have no upgrade

android/assets/game.atlas

@@ -788,6 +788,20 @@ ImprovementIcons/Quarry
   orig: 100, 100
   offset: 0, 0
   index: -1
+ImprovementIcons/Railroad
+  rotate: false
+  xy: 308, 238
+  size: 100, 100
+  orig: 100, 100
+  offset: 0, 0
+  index: -1
+TileSets/Default/Railroad
+  rotate: false
+  xy: 308, 238
+  size: 100, 100
+  orig: 100, 100
+  offset: 0, 0
+  index: -1
 ImprovementIcons/Road
   rotate: false
   xy: 1838, 170
@@ -1714,7 +1728,7 @@ TechIcons/Radio
   index: -1
 TechIcons/Railroad
   rotate: false
-  xy: 308, 238
+  xy: 2, 226
   size: 100, 100
   orig: 100, 100
   offset: 0, 0
@@ -1789,6 +1803,20 @@ TileSets/Default/CityOverlay
   orig: 100, 100
   offset: 0, 0
   index: -1
+TileSets/Default/CrosshatchHexagon
+  rotate: false
+  xy: 583, 1800
+  size: 273, 236
+  orig: 273, 236
+  offset: 0, 0
+  index: -1
+TileSets/FantasyHex/CrosshatchHexagon
+  rotate: false
+  xy: 583, 1800
+  size: 273, 236
+  orig: 273, 236
+  offset: 0, 0
+  index: -1
 TileSets/Default/FalloutOverlay
   rotate: false
   xy: 2, 1042
@@ -1859,37 +1887,9 @@ TileSets/Default/OasisOverlay
   orig: 100, 100
   offset: 0, 0
   index: -1
-TileSets/Default/Railroad
-  rotate: false
-  xy: 410, 214
-  size: 100, 100
-  orig: 100, 100
-  offset: 0, 0
-  index: -1
-ImprovementIcons/Railroad
-  rotate: false
-  xy: 410, 214
-  size: 100, 100
-  orig: 100, 100
-  offset: 0, 0
-  index: -1
-TileSets/FantasyHex/CrosshatchHexagon
-  rotate: false
-  xy: 583, 1800
-  size: 273, 236
-  orig: 273, 236
-  offset: 0, 0
-  index: -1
-TileSets/Default/CrosshatchHexagon
-  rotate: false
-  xy: 583, 1800
-  size: 273, 236
-  orig: 273, 236
-  offset: 0, 0
-  index: -1
 TileSets/FantasyHex/Railroad
   rotate: false
-  xy: 2, 226
+  xy: 410, 214
   size: 100, 100
   orig: 100, 100
   offset: 0, 0
@@ -2957,6 +2957,20 @@ TechIcons/Writing
   orig: 100, 100
   offset: 0, 0
   index: -1
+TileSets/Default/road
+  rotate: false
+  xy: 512, 90
+  size: 61, 11
+  orig: 61, 11
+  offset: 0, 0
+  index: -1
+TileSets/FantasyHex/road
+  rotate: false
+  xy: 512, 90
+  size: 61, 11
+  orig: 61, 11
+  offset: 0, 0
+  index: -1
 TileSets/FantasyHex/Tiles/Academy
   rotate: false
   xy: 818, 13
@@ -4252,20 +4266,6 @@ TileSets/FantasyHex/Units/Work Boats
   orig: 32, 26
   offset: 0, 0
   index: -1
-TileSets/FantasyHex/road
-  rotate: false
-  xy: 512, 90
-  size: 61, 11
-  orig: 61, 11
-  offset: 0, 0
-  index: -1
-TileSets/Default/road
-  rotate: false
-  xy: 512, 90
-  size: 61, 11
-  orig: 61, 11
-  offset: 0, 0
-  index: -1
 UnitIcons/Submarine
   rotate: false
   xy: 2, 104

android/assets/jsons/Units.json

@@ -25,7 +25,6 @@
 		movement:2,
 		strength:5,
 		cost:25,
-		obsoleteTech:"Scientific Theory",
 		uniques:["Ignores terrain cost"],
 		attackSound:"nonmetalhit"
 	},

tests/src/de/tomgrill/gdxtesting/examples/BasicTests.java

@@ -5,10 +5,13 @@ package de.tomgrill.gdxtesting.examples;
 import com.badlogic.gdx.Gdx;
 import com.unciv.UncivGame;
 import com.unciv.models.ruleset.Ruleset;
+import com.unciv.models.ruleset.unit.BaseUnit;
 
 import org.junit.Test;
 import org.junit.runner.RunWith;
 
+import java.util.Collection;
+
 import de.tomgrill.gdxtesting.GdxTestRunner;
 
 import static org.junit.Assert.assertTrue;
@@ -37,6 +40,21 @@ public class BasicTests {
 						&& !new UncivGame("").getViewEntireMapForDebug());
 	}
 
+	// If there's a unit that obsoletes with no upgrade then when it obsoletes
+	// and we try to work on its upgrade, we'll get an exception - see techManager
+	@Test
+	public void allObsoletingUnitsHaveUpgrades() {
+		Collection<BaseUnit> units = new Ruleset(true).getUnits().values();
+		boolean allObsoletingUnitsHaveUpgrades = true;
+		for(BaseUnit unit : units){
+			if(unit.getObsoleteTech()!=null && unit.getUpgradesTo()==null) {
+				System.out.println(unit.name+" obsoletes but has no upgrade");
+				allObsoletingUnitsHaveUpgrades=false;
+			}
+		}
+		assertTrue(allObsoletingUnitsHaveUpgrades);
+	}
+
 
 //	@Test
 //	public void setMapEditorScreen() {