diff --git a/core/src/com/unciv/logic/GameInfo.kt b/core/src/com/unciv/logic/GameInfo.kt
index de19446842..1689cd3829 100644
--- a/core/src/com/unciv/logic/GameInfo.kt
+++ b/core/src/com/unciv/logic/GameInfo.kt
@@ -2,7 +2,6 @@ package com.unciv.logic
 
 import com.badlogic.gdx.graphics.Color
 import com.unciv.Constants
-import com.unciv.models.metadata.GameParameters
 import com.unciv.logic.automation.NextTurnAutomation
 import com.unciv.logic.city.CityConstructions
 import com.unciv.logic.civilization.CivilizationInfo
@@ -12,11 +11,15 @@ import com.unciv.logic.map.TileInfo
 import com.unciv.logic.map.TileMap
 import com.unciv.models.gamebasics.Difficulty
 import com.unciv.models.gamebasics.GameBasics
+import com.unciv.models.metadata.GameParameters
 import java.util.*
 
 class GameInfo {
     @Transient lateinit var difficultyObject: Difficulty // Since this is static game-wide, and was taking a large part of nextTurn
     @Transient lateinit var currentPlayerCiv:CivilizationInfo // this is called thousands of times, no reason to search for it with a find{} every time
+    /** This is used in multiplayer games, where I may have a saved game state on my phone
+     * that is inconsistent with the saved game on the cloud */
+    @Transient var isUpToDate=false
 
     var civilizations = mutableListOf<CivilizationInfo>()
     var difficulty="Chieftain" // difficulty is game-wide, think what would happen if 2 human players could play on different difficulties?
diff --git a/core/src/com/unciv/logic/GameStarter.kt b/core/src/com/unciv/logic/GameStarter.kt
index 3531b29117..e86a5787f3 100644
--- a/core/src/com/unciv/logic/GameStarter.kt
+++ b/core/src/com/unciv/logic/GameStarter.kt
@@ -6,8 +6,8 @@ import com.unciv.logic.civilization.CivilizationInfo
 import com.unciv.logic.map.BFS
 import com.unciv.logic.map.TileInfo
 import com.unciv.logic.map.TileMap
-import com.unciv.models.metadata.GameParameters
 import com.unciv.models.gamebasics.GameBasics
+import com.unciv.models.metadata.GameParameters
 import java.util.*
 import kotlin.collections.ArrayList
 
@@ -18,6 +18,7 @@ class GameStarter{
         gameInfo.gameParameters = newGameParameters
         gameInfo.tileMap = TileMap(newGameParameters)
         gameInfo.tileMap.gameInfo = gameInfo // need to set this transient before placing units in the map
+        gameInfo.difficulty = newGameParameters.difficulty
 
 
         val availableCivNames = Stack<String>()
@@ -34,8 +35,8 @@ class GameStarter{
             else availableCivNames.pop()
 
             val playerCiv = CivilizationInfo(nationName)
-            gameInfo.difficulty = newGameParameters.difficulty
             playerCiv.playerType = player.playerType
+            playerCiv.playerId = player.playerId
             gameInfo.civilizations.add(playerCiv)
         }
 
diff --git a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
index 685ef3bbdb..25a59e2c73 100644
--- a/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
+++ b/core/src/com/unciv/logic/civilization/CivilizationInfo.kt
@@ -42,9 +42,10 @@ class CivilizationInfo {
     @Transient var statsForNextTurn = Stats()
     @Transient var detailedCivResources = ResourceSupplyList()
 
+    var playerType = PlayerType.AI
+    /** Used in online multiplayer for human players */ var playerId = ""
     var gold = 0
     @Deprecated("As of 2.11.1") var difficulty = "Chieftain"
-    var playerType = PlayerType.AI
     var civName = ""
     var tech = TechManager()
     var policies = PolicyManager()
diff --git a/core/src/com/unciv/ui/mapeditor/MapEditorOptionsTable.kt b/core/src/com/unciv/ui/mapeditor/MapEditorOptionsTable.kt
index bb63f64d5b..41a79061d7 100644
--- a/core/src/com/unciv/ui/mapeditor/MapEditorOptionsTable.kt
+++ b/core/src/com/unciv/ui/mapeditor/MapEditorOptionsTable.kt
@@ -96,9 +96,9 @@ class MapEditorOptionsTable(mapEditorScreen: MapEditorScreen): PopupTable(mapEdi
         exitMapEditorButton.onClick { UnCivGame.Current.setWorldScreen(); mapEditorScreen.dispose() }
         add(exitMapEditorButton ).row()
 
-        val closeOptionsButtton = TextButton("Close".tr(), skin)
-        closeOptionsButtton.onClick { remove() }
-        add(closeOptionsButtton).row()
+        val closeOptionsButton = TextButton("Close".tr(), skin)
+        closeOptionsButton.onClick { close() }
+        add(closeOptionsButton).row()
 
         open()
     }
@@ -125,7 +125,7 @@ class MapDownloadTable(mapEditorScreen: MapEditorScreen):PopupTable(mapEditorScr
         } catch (ex: Exception) {
             addGoodSizedLabel("Could not get list of maps!").row()
         }
-        addButton("Close") { remove() }
+        addButton("Close") { close() }
         open()
     }
 }
\ No newline at end of file
diff --git a/core/src/com/unciv/ui/newgamescreen/NewGameScreen.kt b/core/src/com/unciv/ui/newgamescreen/NewGameScreen.kt
index 9a2c09382a..ad06154efc 100644
--- a/core/src/com/unciv/ui/newgamescreen/NewGameScreen.kt
+++ b/core/src/com/unciv/ui/newgamescreen/NewGameScreen.kt
@@ -15,6 +15,7 @@ import com.unciv.ui.utils.enable
 import com.unciv.ui.utils.onClick
 import com.unciv.ui.worldscreen.WorldScreen
 import com.unciv.ui.worldscreen.optionstable.PopupTable
+import java.util.*
 import kotlin.concurrent.thread
 
 class NewGameScreen: PickerScreen(){
@@ -34,13 +35,28 @@ class NewGameScreen: PickerScreen(){
         rightSideButton.setText("Start game!".tr())
         rightSideButton.onClick {
             if (newGameParameters.players.none { it.playerType == PlayerType.Human }) {
-                val popup = PopupTable(this)
-                popup.addGoodSizedLabel("No human players selected!").row()
-                popup.addButton("Close") { popup.remove() }
-                popup.open()
+                val noHumanPlayersPopup = PopupTable(this)
+                noHumanPlayersPopup.addGoodSizedLabel("No human players selected!").row()
+                noHumanPlayersPopup.addButton("Close") { noHumanPlayersPopup.close() }
+                noHumanPlayersPopup.open()
                 return@onClick
             }
 
+            if (newGameParameters.isOnlineMultiplayer){
+                for(player in newGameParameters.players.filter{ it.playerType == PlayerType.Human}) {
+                    try {
+                        UUID.fromString(player.playerId)
+                    }
+                    catch (ex:Exception) {
+                        val invalidPlayerIdPopup = PopupTable(this)
+                        invalidPlayerIdPopup.addGoodSizedLabel("Invalid player ID!").row()
+                        invalidPlayerIdPopup.addButton("Close") { invalidPlayerIdPopup.remove() }
+                        invalidPlayerIdPopup.open()
+                        return@onClick
+                    }
+                }
+            }
+
             Gdx.input.inputProcessor = null // remove input processing - nothing will be clicked!
             rightSideButton.disable()
             rightSideButton.setText("Working...".tr())
@@ -50,10 +66,10 @@ class NewGameScreen: PickerScreen(){
                 try {
                     newGame = GameStarter().startNewGame(newGameParameters)
                 } catch (exception: Exception) {
-                    val popup = PopupTable(this)
-                    popup.addGoodSizedLabel("It looks like we can't make a map with the parameters you requested!".tr()).row()
-                    popup.addGoodSizedLabel("Maybe you put too many players into too small a map?".tr()).row()
-                    popup.open()
+                    val cantMakeThatMapPopup = PopupTable(this)
+                    cantMakeThatMapPopup.addGoodSizedLabel("It looks like we can't make a map with the parameters you requested!".tr()).row()
+                    cantMakeThatMapPopup.addGoodSizedLabel("Maybe you put too many players into too small a map?".tr()).row()
+                    cantMakeThatMapPopup.open()
                 }
             }
         }
diff --git a/core/src/com/unciv/ui/newgamescreen/PlayerPickerTable.kt b/core/src/com/unciv/ui/newgamescreen/PlayerPickerTable.kt
index a6b055a92c..43a0f7b35a 100644
--- a/core/src/com/unciv/ui/newgamescreen/PlayerPickerTable.kt
+++ b/core/src/com/unciv/ui/newgamescreen/PlayerPickerTable.kt
@@ -86,8 +86,6 @@ class PlayerPickerTable(val newGameScreen: NewGameScreen, val newGameParameters:
             playerIdTable.add(setCurrentUserButton)
 
             playerTable.add(playerIdTable).colspan(playerTable.columns)
-
-
         }
 
         return playerTable
@@ -111,7 +109,7 @@ class PlayerPickerTable(val newGameScreen: NewGameScreen, val newGameParameters:
 
                 nationListTable.add(NationTable(nation, halfWidth) {
                     player.chosenCiv = nation.name
-                    nationsPopup.remove()
+                    nationsPopup.close()
                     update()
                 }).pad(10f).width(halfWidth).row()
             }
diff --git a/core/src/com/unciv/ui/worldscreen/AlertPopup.kt b/core/src/com/unciv/ui/worldscreen/AlertPopup.kt
index af37eca665..da7498126d 100644
--- a/core/src/com/unciv/ui/worldscreen/AlertPopup.kt
+++ b/core/src/com/unciv/ui/worldscreen/AlertPopup.kt
@@ -101,9 +101,9 @@ class AlertPopup(val worldScreen: WorldScreen, val popupAlert: PopupAlert): Popu
         worldScreen.alertPopupIsOpen = true
     }
 
-    fun close(){
+    override fun close(){
         worldScreen.viewingCiv.popupAlerts.remove(popupAlert)
         worldScreen.alertPopupIsOpen = false
-        remove()
+        super.close()
     }
 }
\ No newline at end of file
diff --git a/core/src/com/unciv/ui/worldscreen/TradePopup.kt b/core/src/com/unciv/ui/worldscreen/TradePopup.kt
index 4e78eafc4d..fea7959378 100644
--- a/core/src/com/unciv/ui/worldscreen/TradePopup.kt
+++ b/core/src/com/unciv/ui/worldscreen/TradePopup.kt
@@ -43,13 +43,13 @@ class TradePopup(worldScreen: WorldScreen): PopupTable(worldScreen){
             tradeLogic.currentTrade.set(trade)
             tradeLogic.acceptTrade()
             currentPlayerCiv.tradeRequests.remove(tradeRequest)
-            remove()
+            close()
             PopupTable(worldScreen).apply {
                 add(otherCivLeaderName.toLabel()).colspan(2)
                 addSeparator()
                 addGoodSizedLabel("Excellent!").row()
                 addButton("Farewell."){
-                    this.remove()
+                    close()
                     worldScreen.shouldUpdate=true
                     // in all cases, worldScreen.shouldUpdate should be set to true when we remove the last of the popups
                     // in order for the next trade to appear immediately
@@ -68,14 +68,14 @@ class TradePopup(worldScreen: WorldScreen): PopupTable(worldScreen){
             if(trade.ourOffers.any{ it.type==TradeType.Treaty && it.name== Constants.peaceTreaty })
                 diplomacyManager.setFlag(DiplomacyFlags.DeclinedPeace,5)
 
-            remove()
+            close()
             requestingCiv.addNotification("[${currentPlayerCiv.civName}] has denied your trade request", Color.GOLD)
 
             worldScreen.shouldUpdate=true
         }
         addButton("How about something else...".tr()){
             currentPlayerCiv.tradeRequests.remove(tradeRequest)
-            remove()
+            close()
 
             val diplomacyScreen= DiplomacyScreen()
             val tradeTable =  diplomacyScreen.setTrade(requestingCiv)
diff --git a/core/src/com/unciv/ui/worldscreen/WorldScreen.kt b/core/src/com/unciv/ui/worldscreen/WorldScreen.kt
index 8758eed9c9..a5b8dbe0d8 100644
--- a/core/src/com/unciv/ui/worldscreen/WorldScreen.kt
+++ b/core/src/com/unciv/ui/worldscreen/WorldScreen.kt
@@ -26,6 +26,7 @@ import com.unciv.ui.trade.DiplomacyScreen
 import com.unciv.ui.utils.*
 import com.unciv.ui.worldscreen.bottombar.BattleTable
 import com.unciv.ui.worldscreen.bottombar.WorldScreenBottomBar
+import com.unciv.ui.worldscreen.optionstable.PopupTable
 import com.unciv.ui.worldscreen.unit.UnitActionsTable
 import kotlin.concurrent.thread
 
@@ -99,6 +100,20 @@ class WorldScreen(val viewingCiv:CivilizationInfo) : CameraStageBaseScreen() {
         tileMapHolder.setCenterPosition(tileToCenterOn,true)
 
         update()
+
+        if(gameInfo.gameParameters.isOnlineMultiplayer && !gameInfo.isUpToDate){
+            val loadingGamePopup = PopupTable(this)
+            loadingGamePopup.add("Loading latest game state...")
+            loadingGamePopup.open()
+            thread {
+                try{
+                    // todo!!!
+                }
+                catch (ex:Exception){
+                    loadingGamePopup.close()
+                }
+            }
+        }
     }
 
     // This is private so that we will set the shouldUpdate to true instead.
diff --git a/core/src/com/unciv/ui/worldscreen/optionstable/PopupTable.kt b/core/src/com/unciv/ui/worldscreen/optionstable/PopupTable.kt
index fb9422e5a1..dc7acc6406 100644
--- a/core/src/com/unciv/ui/worldscreen/optionstable/PopupTable.kt
+++ b/core/src/com/unciv/ui/worldscreen/optionstable/PopupTable.kt
@@ -6,7 +6,6 @@ import com.badlogic.gdx.scenes.scene2d.ui.Label
 import com.badlogic.gdx.scenes.scene2d.ui.Table
 import com.badlogic.gdx.scenes.scene2d.ui.TextButton
 import com.badlogic.gdx.utils.Align
-import com.unciv.UnCivGame
 import com.unciv.models.gamebasics.tr
 import com.unciv.ui.utils.*
 
@@ -25,6 +24,8 @@ open class PopupTable(val screen: CameraStageBaseScreen): Table(CameraStageBaseS
         screen.stage.addActor(this)
     }
 
+    open fun close(){ remove() }
+
     fun addGoodSizedLabel(text: String): Cell<Label> {
         val label = text.toLabel()
         label.setWrap(true)
@@ -39,20 +40,3 @@ open class PopupTable(val screen: CameraStageBaseScreen): Table(CameraStageBaseS
     }
 }
 
-class YesNoPopupTable(question:String, action:()->Unit,
-                      screen: CameraStageBaseScreen = UnCivGame.Current.worldScreen) : PopupTable(screen){
-    init{
-        if(!screen.hasPopupOpen) {
-            screen.hasPopupOpen=true
-            add(question.toLabel()).colspan(2).row()
-            add(TextButton("No".tr(), skin).onClick { close() })
-            add(TextButton("Yes".tr(), skin).onClick { close(); action() })
-            open()
-        }
-    }
-
-    fun close(){
-        remove()
-        screen.hasPopupOpen=false
-    }
-}
\ No newline at end of file
diff --git a/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenMenuTable.kt b/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenMenuTable.kt
index 4d8de0dffc..af0f603093 100644
--- a/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenMenuTable.kt
+++ b/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenMenuTable.kt
@@ -5,9 +5,9 @@ import com.unciv.UnCivGame
 import com.unciv.logic.map.RoadStatus
 import com.unciv.models.gamebasics.tr
 import com.unciv.ui.CivilopediaScreen
-import com.unciv.ui.newgamescreen.NewGameScreen
 import com.unciv.ui.VictoryScreen
 import com.unciv.ui.mapeditor.MapEditorScreen
+import com.unciv.ui.newgamescreen.NewGameScreen
 import com.unciv.ui.pickerscreens.PolicyPickerScreen
 import com.unciv.ui.saves.LoadGameScreen
 import com.unciv.ui.saves.SaveGameScreen
@@ -65,7 +65,7 @@ class WorldScreenMenuTable(val worldScreen: WorldScreen) : PopupTable(worldScree
             remove()
         }
 
-        addButton("Close".tr()){ remove() }
+        addButton("Close".tr()){ close() }
 
         open()
     }
@@ -83,7 +83,7 @@ class WorldScreenCommunityTable(val worldScreen: WorldScreen) : PopupTable(world
             remove()
         }
 
-        addButton("Close".tr()){ remove() }
+        addButton("Close".tr()){ close() }
 
         open()
     }
diff --git a/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenOptionsTable.kt b/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenOptionsTable.kt
index ef99eab217..19b31522c6 100644
--- a/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenOptionsTable.kt
+++ b/core/src/com/unciv/ui/worldscreen/optionstable/WorldScreenOptionsTable.kt
@@ -96,7 +96,7 @@ class WorldScreenOptionsTable(val worldScreen:WorldScreen) : PopupTable(worldScr
         scrollPane.setScrollingDisabled(true,false)
         add(scrollPane).maxHeight(screen.stage.height*0.6f).row()
 
-        addButton("Close"){ remove() }
+        addButton("Close"){ close() }
 
         pack() // Needed to show the background.
         center(UnCivGame.Current.worldScreen.stage)
diff --git a/core/src/com/unciv/ui/worldscreen/optionstable/YesNoPopupTable.kt b/core/src/com/unciv/ui/worldscreen/optionstable/YesNoPopupTable.kt
new file mode 100644
index 0000000000..663aeac779
--- /dev/null
+++ b/core/src/com/unciv/ui/worldscreen/optionstable/YesNoPopupTable.kt
@@ -0,0 +1,26 @@
+package com.unciv.ui.worldscreen.optionstable
+
+import com.badlogic.gdx.scenes.scene2d.ui.TextButton
+import com.unciv.UnCivGame
+import com.unciv.models.gamebasics.tr
+import com.unciv.ui.utils.CameraStageBaseScreen
+import com.unciv.ui.utils.onClick
+import com.unciv.ui.utils.toLabel
+
+class YesNoPopupTable(question:String, action:()->Unit,
+                      screen: CameraStageBaseScreen = UnCivGame.Current.worldScreen) : PopupTable(screen){
+    init{
+        if(!screen.hasPopupOpen) {
+            screen.hasPopupOpen=true
+            add(question.toLabel()).colspan(2).row()
+            add(TextButton("No".tr(), skin).onClick { close() })
+            add(TextButton("Yes".tr(), skin).onClick { close(); action() })
+            open()
+        }
+    }
+
+    override fun close(){
+        super.close()
+        screen.hasPopupOpen=false
+    }
+}
\ No newline at end of file