diff --git a/client/src/components/DashboardActions.vue b/client/src/components/DashboardActions.vue
index 4eb9bb5..5273ddd 100644
--- a/client/src/components/DashboardActions.vue
+++ b/client/src/components/DashboardActions.vue
@@ -248,11 +248,22 @@ async function handleFileUpload(event: Event) {
     }
     
     const result = await response.json();
-    alert(`Estado cargado exitosamente. ${result.message || 'NameManager actualizado.'}`);
+    const message = result.importedUuids 
+      ? `Estado cargado exitosamente. ${result.importedUuids} UUIDs importados. ${result.message || ''}`
+      : `Estado cargado exitosamente. ${result.message || 'NameManager actualizado.'}`;
+    alert(message);
     
   } catch (error) {
     console.error('Error uploading nameManager state:', error);
-    alert('Error al cargar el estado del nameManager. Verifica que el archivo sea válido.');
+    
+    // Handle different error types
+    if (error.message && error.message.includes('413')) {
+      alert('Error: El archivo es demasiado grande (máximo 50MB). Considera crear un archivo de guardado más pequeño.');
+    } else if (error.message && error.message.includes('400')) {
+      alert('Error: Archivo inválido. Asegúrate de subir un archivo .snatchSave válido.');
+    } else {
+      alert('Error al cargar el estado del nameManager. Verifica que el archivo sea válido y la conexión sea estable.');
+    }
   } finally {
     // Reset file input
     target.value = '';
diff --git a/client/src/views/Leaderboard.vue b/client/src/views/Leaderboard.vue
index 0273714..8328f53 100644
--- a/client/src/views/Leaderboard.vue
+++ b/client/src/views/Leaderboard.vue
@@ -13,8 +13,8 @@
           <span class="collapse-text">{{ filtersCollapsed ? 'Mostrar filtros' : 'Ocultar filtros' }}</span>
         </button>
         <button class="btn" @click="refreshAll" :disabled="loading">{{ loading ? 'Actualizando…' : 'Actualizar' }}</button>
-        <button class="btn" @click="downloadCSV" :disabled="loading" title="Descargar datos actuales como CSV">
-          📊 CSV
+        <button class="btn" @click="downloadJSON" :disabled="loading" title="Descargar datos actuales como JSON">
+          📊 JSON
         </button>
       </div>
     </div>
@@ -236,6 +236,11 @@ function computeMetricsFromScores() {
     if (player.name) {
       totalPlayersWithNames++;
       
+      // Count players with shame tokens
+      if (player.shameTokens && player.shameTokens > 0) {
+        playersWithShame++;
+      }
+      
       // Extract scores from roomScoreHistory if available
       if (player.roomScoreHistory) {
         player.roomScoreHistory.forEach((roomScore: any) => {
@@ -273,13 +278,13 @@ function computeMetricsFromScores() {
 // Function to compute metrics for a selected player
 function computeSelectedPlayerMetrics(uuid: string) {
   const playerData = allPlayersWithScores.value.find(p => p.uuid === uuid);
-  if (!playerData?.roomScoreHistory) {
+  if (!playerData) {
     selectedPlayerMetrics.value = {
       players_seated: 1,
       score_p1: 0,
       score_p2: 0,
       players_with_shame: 0,
-      players_without_shame: 0
+      players_without_shame: 1
     };
     return;
   }
@@ -288,30 +293,34 @@ function computeSelectedPlayerMetrics(uuid: string) {
   let totalP2Scores = 0;
   let p1Count = 0;
   let p2Count = 0;
+  
+  const hasShame = playerData.shameTokens && playerData.shameTokens > 0;
 
-  playerData.roomScoreHistory.forEach((roomScore: any) => {
-    roomScore.scores.forEach((score: any) => {
-      // Apply filters to scores
-      if (!scorePassesFilters(score, roomScore.roomId)) {
-        return;
-      }
-      
-      if (score.role === 'P1') {
-        totalP1Scores += score.score;
-        p1Count++;
-      } else if (score.role === 'P2') {
-        totalP2Scores += score.score;
-        p2Count++;
-      }
+  if (playerData.roomScoreHistory) {
+    playerData.roomScoreHistory.forEach((roomScore: any) => {
+      roomScore.scores.forEach((score: any) => {
+        // Apply filters to scores
+        if (!scorePassesFilters(score, roomScore.roomId)) {
+          return;
+        }
+        
+        if (score.role === 'P1') {
+          totalP1Scores += score.score;
+          p1Count++;
+        } else if (score.role === 'P2') {
+          totalP2Scores += score.score;
+          p2Count++;
+        }
+      });
     });
-  });
+  }
 
   selectedPlayerMetrics.value = {
     players_seated: 1,
     score_p1: p1Count > 0 ? Math.round((totalP1Scores / p1Count) * 10) / 10 : 0,
     score_p2: p2Count > 0 ? Math.round((totalP2Scores / p2Count) * 10) / 10 : 0,
-    players_with_shame: 0, // Would need shame data
-    players_without_shame: 0
+    players_with_shame: hasShame ? 1 : 0,
+    players_without_shame: hasShame ? 0 : 1
   };
 }
 
@@ -815,86 +824,82 @@ watch(() => playersFiltered.value.length, () => {
 const allPlayersActions = ref<{ uuid: string; name: string; total: number }[]>([]);
 
 
-function downloadCSV() {
-  const currentEvents = eventFilters.currentSourceEvents.value;
-  
-  // Create CSV headers
-  const headers = ['Type', 'Event', 'Count', 'Round', 'GameVariant', 'PlayerUuid', 'PlayerName', 'RoomId', 'DataSource'];
-  
-  // Create CSV rows - one row per individual event occurrence
-  const rows: string[][] = [];
-  
-  // Add detailed individual event rows if we have detailed data
-  currentEvents.forEach(event => {
-    if (EVENTS.includes(event.kind)) {
-      rows.push([
-        'event',
-        event.kind,
-        '1',
-        event.round?.toString() || '',
-        event.gameVariant || '',
-        event.playerUuid || '',
-        event.playerName || '',
-        event.roomId || '',
-        eventFilters.dataSource.value
-      ]);
-    }
-  });
-  
-  // Also add per-player aggregated data from playersActionsByUuid
-  Object.entries(playersActionsByUuid.value).forEach(([uuid, counts]) => {
-    const player = players.value.find(p => p.uuid === uuid);
-    EVENTS.forEach(eventType => {
-      const count = counts[eventType] || 0;
-      if (count > 0) {
-        // Add one row per occurrence for proper import compatibility
-        for (let i = 0; i < count; i++) {
-          rows.push([
-            'event',
-            eventType,
-            '1',
-            '', // Round info not available in aggregated player data
-            '', // GameVariant info not available in aggregated player data  
-            uuid,
-            player?.name || '',
-            '', // Room info not available in aggregated player data
-            'player-aggregated'
-          ]);
-        }
+function downloadJSON() {
+  // Create a comprehensive snapshot of current interface data
+  const currentData = {
+    metadata: {
+      timestamp: new Date().toISOString(),
+      dataSource: eventFilters.dataSource.value,
+      filters: {
+        room: eventFilters.roomFilter.value,
+        round: eventFilters.roundFilter.value,
+        game: eventFilters.gameFilter.value,
+        hasActiveFilters: eventFilters.hasActiveFilters.value,
+        filterSummary: eventFilters.filterSummary.value,
+        selectedPlayer: selectedUuid.value ? {
+          uuid: selectedUuid.value,
+          name: players.value.find(p => p.uuid === selectedUuid.value)?.name || 'Jugador'
+        } : null,
+        selectedRoom: selectedRoomId.value ? {
+          roomId: selectedRoomId.value,
+          name: availableRooms.value.find(r => r.roomId === selectedRoomId.value)?.name || 'Sala'
+        } : null
       }
-    });
-  });
+    },
+    
+    // Current chart totals being displayed
+    chartTotals: {
+      offers: offersTotal.value,
+      responses: responsesTotal.value,
+      force: forceTotal.value,
+      shame: shameTotal.value,
+      report: reportTotal.value,
+      averageScore: averageScoreTotal.value,
+      totalPlayers: totalPlayersCount.value
+    },
+    
+    // Global event counts (filtered)
+    globalEventCounts: eventFilters.globalEventCounts.value,
+    
+    // Selected player event counts (if applicable)
+    selectedPlayerEventCounts: selectedUuid.value ? playerEventCounts.value : null,
+    
+    // Additional metrics being displayed
+    additionalMetrics: additionalMetrics.value,
+    
+    // Selected player metrics (if applicable) 
+    selectedPlayerMetrics: selectedUuid.value ? selectedPlayerMetrics.value : null,
+    
+    // Combined counts used in charts
+    combinedGlobalCounts: combinedGlobalCounts.value,
+    combinedPlayerCounts: selectedUuid.value ? combinedPlayerCounts.value : null,
+    
+    // Players data
+    players: players.value,
+    availableRooms: availableRooms.value,
+    
+    // Current filtered data if available
+    currentSourceEvents: eventFilters.currentSourceEvents.value,
+    
+    // Per-player action counts
+    playersActionsByUuid: playersActionsByUuid.value,
+    
+    // All players with scores data
+    allPlayersWithScores: allPlayersWithScores.value.map(player => ({
+      uuid: player.uuid,
+      name: player.name,
+      total: player.total,
+      shameTokens: player.shameTokens,
+      counts: player.counts,
+      roomScoreHistory: player.roomScoreHistory
+    }))
+  };
   
-  // Add metric data
-  const currentMetrics = eventFilters.dataSource.value === 'aggregated' 
-    ? additionalMetrics.value 
-    : additionalMetrics.value; // Same source for now
-  
-  METRICS.forEach(metricType => {
-    const count = currentMetrics[metricType] || 0;
-    if (count > 0) {
-      rows.push([
-        'metric',
-        metricType,
-        count.toString(),
-        '',
-        '',
-        '',
-        '',
-        '',
-        eventFilters.dataSource.value
-      ]);
-    }
-  });
-  
-  // Convert to CSV string
-  const csvContent = [
-    headers.join(','),
-    ...rows.map(row => row.map(cell => `"${cell}"`).join(','))
-  ].join('\n');
+  // Convert to formatted JSON string
+  const jsonString = JSON.stringify(currentData, null, 2);
   
   // Create and download file
-  const blob = new Blob([csvContent], { type: 'text/csv;charset=utf-8;' });
+  const blob = new Blob([jsonString], { type: 'application/json;charset=utf-8;' });
   const link = document.createElement('a');
   const url = URL.createObjectURL(blob);
   link.setAttribute('href', url);
@@ -903,7 +908,7 @@ function downloadCSV() {
   const timestamp = new Date().toISOString().slice(0, 19).replace(/[T:]/g, '-');
   const dataSourceLabel = eventFilters.dataSource.value === 'aggregated' ? 'agregados' : 'activos';
   const filterLabel = eventFilters.hasActiveFilters.value ? `_${eventFilters.filterSummary.value.replace(/\s+/g, '_')}` : '';
-  const filename = `datos_${dataSourceLabel}${filterLabel}_${timestamp}.csv`;
+  const filename = `leaderboard_${dataSourceLabel}${filterLabel}_${timestamp}.json`;
   
   link.setAttribute('download', filename);
   link.style.visibility = 'hidden';
diff --git a/server/src/adminApi.ts b/server/src/adminApi.ts
index e4ab28f..291f416 100644
--- a/server/src/adminApi.ts
+++ b/server/src/adminApi.ts
@@ -938,7 +938,8 @@ async function sendPlayersActionsUpdate(client?: Response) {
         total,
         detailedHistory,
         rawHistory: history,
-        roomScoreHistory
+        roomScoreHistory,
+        shameTokens: nameManager.getShameTokens(uuid)
       };
     }).filter((p: any) => p.total > 0 || p.name);
 
@@ -977,23 +978,49 @@ adminRouter.post("/admin/namemanager/import", async (req: Request, res: Response
     const nameManager = NameManager.getInstance();
     const state = req.body;
     
-    if (!state || !state.data) {
-      return res.status(400).json({ error: 'Invalid state format' });
+    // Validate request size and format
+    if (!state) {
+      return res.status(400).json({ error: 'No data provided' });
     }
     
+    if (!state.data) {
+      return res.status(400).json({ 
+        error: 'Invalid state format - missing data property',
+        hint: 'Ensure you are uploading a valid .snatchSave file'
+      });
+    }
+    
+    console.log(`[AdminAPI] Importing nameManager state - Version: ${state.version || 'unknown'}`);
+    
     nameManager.importState(state);
     
     // Broadcast update to SSE clients after importing
     await sendUuidsUpdate();
     await sendPlayersActionsUpdate();
     
+    const importedUuids = nameManager.getAllKnownUuids().length;
+    console.log(`[AdminAPI] Successfully imported nameManager state with ${importedUuids} UUIDs`);
+    
     res.json({ 
       success: true, 
-      message: `NameManager state imported successfully. Version: ${state.version || 'unknown'}` 
+      message: `NameManager state imported successfully. Version: ${state.version || 'unknown'}, UUIDs: ${importedUuids}`,
+      importedUuids
     });
   } catch (error) {
     console.error('[AdminAPI] Error importing nameManager state:', error);
-    res.status(500).json({ error: 'Failed to import nameManager state', details: error.message });
+    
+    // Handle specific error types
+    if (error.message && error.message.includes('PayloadTooLargeError')) {
+      return res.status(413).json({ 
+        error: 'File too large', 
+        details: 'The save file is too large to process. Maximum size: 50MB' 
+      });
+    }
+    
+    res.status(500).json({ 
+      error: 'Failed to import nameManager state', 
+      details: error.message 
+    });
   }
 });
 
diff --git a/server/src/index.ts b/server/src/index.ts
index 6860592..7bed675 100644
--- a/server/src/index.ts
+++ b/server/src/index.ts
@@ -12,7 +12,8 @@ const port = Number(process.env.PORT) || 3000;
 const app = express();
 
 app.use(cors());
-app.use(express.json());
+app.use(express.json({ limit: '50mb' }));
+app.use(express.urlencoded({ limit: '50mb', extended: true }));
 
 const server = createServer(app);
 const gameServer = new Server({