diff --git a/core/src/com/unciv/logic/GameInfo.kt b/core/src/com/unciv/logic/GameInfo.kt
index e31b37b895..d1c26eea12 100644
--- a/core/src/com/unciv/logic/GameInfo.kt
+++ b/core/src/com/unciv/logic/GameInfo.kt
@@ -92,6 +92,8 @@ class GameInfo {
             tile = viableTiles.getRandom()
         }
 
+        // if we don't make this into a separate list then the retain() will happen on the Tech keys,
+        // which effectively removes those techs from the game and causes all sorts of problems
         val allResearchedTechs = GameBasics.Technologies.keys.toMutableList()
         for (civ in civilizations.filter { !it.isBarbarianCivilization() && !it.isDefeated() }) {
             allResearchedTechs.retainAll(civ.tech.techsResearched)
diff --git a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
index 5019155442..13ef8686f2 100644
--- a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
+++ b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
@@ -70,7 +70,7 @@ class CivilizationInfo {
 
     constructor(civName: String) {
         this.civName = civName
-        tech.techsResearched.add("Agriculture")
+        tech.addTechnology("Agriculture")
     }
 
     fun clone(): CivilizationInfo {
diff --git a/core/src/com/unciv/logic/map/MapUnit.kt b/core/src/com/unciv/logic/map/MapUnit.kt
index d683060012..fcbf6d34b9 100644
--- a/core/src/com/unciv/logic/map/MapUnit.kt
+++ b/core/src/com/unciv/logic/map/MapUnit.kt
@@ -416,8 +416,7 @@ class MapUnit {
         if(researchableAncientEraTechs.isNotEmpty())
             actions.add {
                 val tech = researchableAncientEraTechs.getRandom().name
-                civInfo.tech.techsResearched.add(tech)
-                if(civInfo.tech.techsToResearch.contains(tech)) civInfo.tech.techsToResearch.remove(tech)
+                civInfo.tech.addTechnology(tech)
                 civInfo.addNotification("We have discovered the lost technology of [$tech] in the ruins!",currentTile.position, Color.BLUE)
             }
 
diff --git a/core/src/com/unciv/ui/saves/LoadScreen.kt b/core/src/com/unciv/ui/saves/LoadScreen.kt
index 8e1c15e729..febf54bc9a 100644
--- a/core/src/com/unciv/ui/saves/LoadScreen.kt
+++ b/core/src/com/unciv/ui/saves/LoadScreen.kt
@@ -82,7 +82,6 @@ class LoadScreen : PickerScreen() {
             UnCivGame.Current.loadGame(selectedSave)
         }
 
-
     }
 
 }
\ No newline at end of file