diff --git a/build.gradle b/build.gradle
index 4982834679..83c33b558d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -33,8 +33,8 @@ allprojects {
     version = '1.0.1'
     ext {
         appName = "Unciv"
-        appCodeNumber = 413
-        appVersion = "3.7.6"
+        appCodeNumber = 414
+        appVersion = "3.7.6-patch1"
 
         gdxVersion = '1.9.10'
         roboVMVersion = '2.3.1'
diff --git a/core/src/com/unciv/logic/civilization/TechManager.kt b/core/src/com/unciv/logic/civilization/TechManager.kt
index 8d048f51f7..68cec6cdb6 100644
--- a/core/src/com/unciv/logic/civilization/TechManager.kt
+++ b/core/src/com/unciv/logic/civilization/TechManager.kt
@@ -257,12 +257,19 @@ class TechManager {
         }
 
         val obsoleteUnits = getRuleset().units.values.filter { it.obsoleteTech == techName }.map { it.name }
-        for (city in civInfo.cities)
-            for(constructionName in city.cityConstructions.constructionQueue.toList()){ // copy, since we're changing the queue
-                if(constructionName !in obsoleteUnits) continue
-                val constructionUnit = city.cityConstructions.getConstruction(constructionName) as BaseUnit
-                city.cityConstructions.constructionQueue.replaceAll { if(it==constructionName) constructionUnit.upgradesTo!! else it }
+        for (city in civInfo.cities) {
+                // Do not use replaceAll - that's a Java 8 feature and will fail on older phones!
+            val oldQueue = city.cityConstructions.constructionQueue.toList()  // copy, since we're changing the queue
+            city.cityConstructions.constructionQueue.clear()
+            for (constructionName in oldQueue) {
+                var newConstructionName = constructionName
+                if (constructionName in obsoleteUnits) {
+                    val constructionUnit = city.cityConstructions.getConstruction(constructionName) as BaseUnit
+                    newConstructionName = civInfo.getEquivalentUnit(constructionUnit.upgradesTo!!).name
+                }
+                city.cityConstructions.constructionQueue.add(newConstructionName)
             }
+        }
 
         if(techName=="Writing" && civInfo.nation.unique == UniqueAbility.INGENUITY
                 && civInfo.cities.any())
diff --git a/core/src/com/unciv/logic/map/TileInfo.kt b/core/src/com/unciv/logic/map/TileInfo.kt
index 5944e596e8..dbb6030a96 100644
--- a/core/src/com/unciv/logic/map/TileInfo.kt
+++ b/core/src/com/unciv/logic/map/TileInfo.kt
@@ -80,14 +80,10 @@ open class TileInfo {
     //region pure functions
 
     /** Returns military, civilian and air units in tile */
-    fun getUnits(): Sequence<MapUnit> {
-        if(militaryUnit==null && civilianUnit==null && airUnits.isEmpty())
-            return emptySequence() // for performance reasons - costs much less to initialize than an empty ArrayList or list()
-        val list = ArrayList<MapUnit>(2)
-        if(militaryUnit!=null) list.add(militaryUnit!!)
-        if(civilianUnit!=null) list.add(civilianUnit!!)
-        list.addAll(airUnits)
-        return list.asSequence()
+    fun getUnits() = sequence {
+        if (militaryUnit != null) yield(militaryUnit!!)
+        if (civilianUnit != null) yield(civilianUnit!!)
+        if (airUnits.isNotEmpty()) yieldAll(airUnits)
     }
 
     fun getCity(): CityInfo? = owningCity
@@ -115,7 +111,9 @@ open class TileInfo {
     // This is for performance - since we access the neighbors of a tile ALL THE TIME,
     // and the neighbors of a tile never change, it's much more efficient to save the list once and for all!
     @delegate:Transient
-    val neighbors: Sequence<TileInfo> by lazy { getTilesAtDistance(1) }
+    val neighbors: Sequence<TileInfo> by lazy { getTilesAtDistance(1).toList().asSequence() }
+    // We have to .toList() so that the values are stored together once for caching,
+    // and the toSequence so that aggregations (like neighbors.flatMap{it.units} don't take up their own space
 
     fun getHeight(): Int {
         if (baseTerrain == Constants.mountain) return 4