diff --git a/lib/pages/database_download/database_download_page.dart b/lib/pages/database_download/database_download_page.dart
index c4c492bb8..51803fa82 100644
--- a/lib/pages/database_download/database_download_page.dart
+++ b/lib/pages/database_download/database_download_page.dart
@@ -85,6 +85,21 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
   }
 
   Future<void> downloadFileAndroid() async {
+    try {
+      await downloadFileAndroidWith('latest');
+    } catch(e){
+      await downloadFileAndroidWith('safe');
+    }
+  }
+  Future<void> downloadFileIOS() async {
+    try {
+      await downloadFileIOSWith('latest');
+    } catch(e){
+      await downloadFileIOSWith('safe');
+    }
+  }
+
+  Future<void> downloadFileAndroidWith(String target) async {
     Dio dio = Dio();
     int oneMega = 1024 * 1024;
     int nu = 0;
@@ -105,7 +120,18 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
                 tlatest = tnu;
                 tnu = 0;
               }));
-      await SyncManager.checkSync();
+      switch(target){
+        case 'latest': await SyncManager.checkSyncLatest(); break;
+        case 'safe': await SyncManager.checkSync(); break;
+        default: {
+          try {
+            await downloadFileAndroidWith('latest');
+          } catch(e){
+            await downloadFileAndroidWith('safe');
+          }
+          return;
+        }
+      }
       await dio.download(
           SyncManager.getLatestDB().getDBDownloadUrl(widget.dbType!),
           '${dir.path}/db.sql.7z', onReceiveProgress: (rec, total) {
@@ -162,10 +188,26 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
 
       await DataBaseManager.reloadInstance();
 
-      if (Settings.useOptimizeDatabase) {
-        await deleteUnused();
-
+      try {
+        if (Settings.useOptimizeDatabase) {
+          await deleteUnused();
+          await indexing();
+        }
+      } catch(e1,st1){
+        Logger.error('[Sync-check] E: $e1\n'
+            '$st1');
+      }
+      try {        
+        if (Settings.useOptimizeDatabase) await deleteUnused();
+      } catch(e1,st1){
+        Logger.error('[deleteUnused] E: $e1\n'
+            '$st1');
+      }
+      try {
         await indexing();
+      } catch(e1,st1){
+        Logger.error('[indexing] E: $e1\n'
+            '$st1');
       }
 
       if (widget.isSync == true) {
@@ -181,6 +223,7 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
     } catch (e, st) {
       Logger.error('[DBDownload] E: $e\n'
           '$st');
+      if(target == 'latest') throw e;
     }
 
     setState(() {
@@ -189,7 +232,7 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
     });
   }
 
-  Future<void> downloadFileIOS() async {
+  Future<void> downloadFileIOSWith(String target) async {
     Dio dio = Dio();
     int oneMega = 1024 * 1024;
     int nu = 0;
@@ -210,7 +253,18 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
                 tlatest = tnu;
                 tnu = 0;
               }));
-      await SyncManager.checkSync();
+      switch(target){
+        case 'latest': await SyncManager.checkSyncLatest(); break;
+        case 'safe': await SyncManager.checkSync(); break;
+        default: {
+          try {
+            await downloadFileIOSWith('latest');
+          } catch(e){
+            await downloadFileIOSWith('safe');
+          }
+          return;
+        }
+      }
       await dio.download(
           SyncManager.getLatestDB().getDBDownloadUrliOS(widget.dbType!),
           '$dir/data.db', onReceiveProgress: (rec, total) {
@@ -246,9 +300,18 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
 
       await DataBaseManager.reloadInstance();
 
-      if (Settings.useOptimizeDatabase) await deleteUnused();
-
-      await indexing();
+      try {
+        if (Settings.useOptimizeDatabase) await deleteUnused();
+      } catch(e1,st1){
+        Logger.error('[deleteUnused] E: $e1\n'
+            '$st1');
+      }
+      try {
+        await indexing();
+      } catch(e1,st1){
+        Logger.error('[indexing] E: $e1\n'
+            '$st1');
+      }
 
       if (widget.isSync == true) {
         Navigator.pop(context);
@@ -263,6 +326,7 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
     } catch (e, st) {
       Logger.error('[DBDownload] E: $e\n'
           '$st');
+      if(target == 'latest') throw e;
     }
 
     setState(() {
@@ -275,7 +339,7 @@ class DataBaseDownloadPageState extends State<DataBaseDownloadPage> {
     var sql = HitomiManager.translate2query(
             '${Settings.includeTags} ${Settings.excludeTags.where((e) => e.trim().isNotEmpty).map((e) => '-$e').join(' ')}')
         .replaceAll(' AND ExistOnHitomi=1', '');
-
+    
     await (await DataBaseManager.getInstance()).delete('HitomiColumnModel',
         'NOT (${sql.substring(sql.indexOf('WHERE') + 6)})', []);
   }
diff --git a/lib/version/sync.dart b/lib/version/sync.dart
index 081f4e9fc..c79f31e46 100644
--- a/lib/version/sync.dart
+++ b/lib/version/sync.dart
@@ -125,12 +125,13 @@ class SyncManager {
     } catch (e, st) {
       Logger.error('[Sync-check] E: $e\n'
           '$st');
+      throw e;
     }
   }
 
 
   static Future<void> checkSync() async {
-    for(int i = 0;i < 100;i++){
+    // for(int i = 0;i < 100;i++){
       try {
         var ls = const LineSplitter();
         var infoRaw = (await http.get(syncInfoURL('d2bd5ae068efb26eb4689e5d6281a590e59fc4e2'))).body;
@@ -201,11 +202,11 @@ class SyncManager {
         if (requestSize > ignoreUserAcceptThreshold) syncRequire = true;
         if (_rows!.any((element) => element.type == 'chunk')) chunkRequire = true;
       } catch (e, st) {
-        continue;
+        // continue;
         Logger.error('[Sync-check] E: $e\n'
             '$st');
       }
-    }
+    // }
   }
 
   static SyncInfoRecord getLatestDB() {