diff --git a/Mage.Server/src/main/java/mage/server/MageServerImpl.java b/Mage.Server/src/main/java/mage/server/MageServerImpl.java
index c9e1423485f..7edd074a29e 100644
--- a/Mage.Server/src/main/java/mage/server/MageServerImpl.java
+++ b/Mage.Server/src/main/java/mage/server/MageServerImpl.java
@@ -1004,7 +1004,15 @@ public class MageServerImpl implements MageServer {
         if (ex.getMessage() != null && !ex.getMessage().equals("No message")) {
             throw new MageException("Server error: " + ex.getMessage());
         }
-        logger.error("unknown error", ex); // TODO: on logs spamming (e.g. connection problems) move it inside condition block above
+
+        if (ex instanceof ConcurrentModificationException) {
+            // how-to fix: game objects must be accessible by game thread only, all other threads must work with copies
+            logger.error("wrong threads sync error", ex);
+        } else {
+            // TODO: on logs spamming (e.g. connection problems) move it inside condition block above
+            logger.error("unknown error", ex);
+        }
+
     }
 
     @Override
diff --git a/Mage.Server/src/main/java/mage/server/game/GameSessionWatcher.java b/Mage.Server/src/main/java/mage/server/game/GameSessionWatcher.java
index 3bb4fefae3a..e30c6ced338 100644
--- a/Mage.Server/src/main/java/mage/server/game/GameSessionWatcher.java
+++ b/Mage.Server/src/main/java/mage/server/game/GameSessionWatcher.java
@@ -42,6 +42,8 @@ public class GameSessionWatcher {
         if (!killed) {
             Optional<User> user = userManager.getUser(userId);
             if (user.isPresent()) {
+                // TODO: can be called outside of the game thread, e.g. user start watching already running game
+                //    possible fix: getGameView must use last cached value in non game thread call (split by sessions)
                 user.get().fireCallback(new ClientCallback(ClientCallbackMethod.GAME_INIT, game.getId(), getGameView()));
                 return true;
             }
diff --git a/Mage.Tests/src/test/java/org/mage/test/load/LoadCallbackClient.java b/Mage.Tests/src/test/java/org/mage/test/load/LoadCallbackClient.java
index 4de90ba8779..35046809512 100644
--- a/Mage.Tests/src/test/java/org/mage/test/load/LoadCallbackClient.java
+++ b/Mage.Tests/src/test/java/org/mage/test/load/LoadCallbackClient.java
@@ -34,7 +34,7 @@ public class LoadCallbackClient implements CallbackClient {
 
     private final String logsPrefix;
     private final Boolean showLogsAsHtml; // original game logs in HTML, but it can be converted to txt for more readable console
-    private String globalProgress = ""; // progress 33% [=20.cd, +21, +17], AI game #9: ---
+    private String globalProgress = ""; // example: progress 33% [20.cd, 21.__, 17.__], AI game #09: ---
 
     public LoadCallbackClient(boolean joinGameChat, String logsPrefix, Boolean showLogsAsHtml) {
         this.joinGameChat = joinGameChat;
diff --git a/Mage.Tests/src/test/java/org/mage/test/load/LoadTest.java b/Mage.Tests/src/test/java/org/mage/test/load/LoadTest.java
index 6f7696f163a..16602b23471 100644
--- a/Mage.Tests/src/test/java/org/mage/test/load/LoadTest.java
+++ b/Mage.Tests/src/test/java/org/mage/test/load/LoadTest.java
@@ -51,7 +51,7 @@ public class LoadTest {
     private static final Boolean TEST_SHOW_GAME_LOGS_AS_HTML = false; // html is original format with full data, but can be too bloated
     private static final String TEST_AI_GAME_MODE = "Freeform Commander Free For All";
     private static final String TEST_AI_DECK_TYPE = "Variant Magic - Freeform Commander";
-    private static final String TEST_AI_RANDOM_DECK_SETS = "LCI,LCC,WHO"; // set for random generated decks (empty for all sets usage, PELP for lands only - communication test)
+    private static final String TEST_AI_RANDOM_DECK_SETS = "DFT,DRC"; // set for random generated decks (empty for all sets usage, PELP for lands only - communication test)
     private static final String TEST_AI_RANDOM_DECK_COLORS_FOR_EMPTY_GAME = "GR";  // colors list for deck generation, empty for all colors
     private static final String TEST_AI_RANDOM_DECK_COLORS_FOR_AI_GAME = "WUBRG";
     private static final String TEST_AI_CUSTOM_DECK_PATH_1 = ""; // custom deck file instead random for player 1 (empty for random)
@@ -369,7 +369,7 @@ public class LoadTest {
                 long randomSeed = seedsList.get(i);
                 logger.info("Game " + (i + 1) + " of " + seedsList.size() + ", RANDOM seed: " + randomSeed);
                 Future gameTask = executerService.submit(() -> {
-                    String gameName = "AI game #" + (gameIndex + 1);
+                    String gameName = String.format("AI game #%02d", gameIndex + 1);
                     LoadTestGameResult gameResult = gameResults.createGame(gameIndex + 1, gameName, randomSeed);
                     playTwoAIGame(gameName, gameIndex + 1, tasksProgress, randomSeed, TEST_AI_RANDOM_DECK_COLORS_FOR_AI_GAME, TEST_AI_RANDOM_DECK_SETS, gameResult);
                 });
@@ -606,7 +606,7 @@ public class LoadTest {
         }
 
         private void updateInfo() {
-            // example: progress 33% [=20.cd, +21, +17], AI game #9: ---
+            // example: progress 33% [20.cd, 21.__, 17.__], AI game #09: ---
 
             int completed = this.finishes.values().stream().mapToInt(x -> x.isEmpty() ? 0 : 1).sum();
             int completedPercent = this.finishes.size() == 0 ? 0 : completed * 100 / this.finishes.size();
@@ -617,10 +617,10 @@ public class LoadTest {
                         String finishInfo = this.finishes.getOrDefault(taskNumber, "");
                         if (finishInfo.isEmpty()) {
                             // active
-                            return "+" + turn;
+                            return turn + ".__";
                         } else {
                             // done
-                            return "=" + turn + "." + finishInfo;
+                            return turn + "." + finishInfo;
                         }
                     })
                     .collect(Collectors.joining(", "));