diff --git a/FileLiberator/DownloadBook.cs b/FileLiberator/DownloadBook.cs
index cd69c2c1..c32aa51e 100644
--- a/FileLiberator/DownloadBook.cs
+++ b/FileLiberator/DownloadBook.cs
@@ -39,7 +39,7 @@ namespace FileLiberator
 			=> FileUtility.GetValidFilename(
 				AudibleFileStorage.DownloadsInProgress,
 				libraryBook.Book.Title,
-				"aax",
+				"aaxc",
 				libraryBook.Book.AudibleProductId);
 
 		private async Task<string> downloadAaxcBookAsync(LibraryBook libraryBook, string tempAaxFilename)
diff --git a/LibationLauncher/LibationLauncher.csproj b/LibationLauncher/LibationLauncher.csproj
index cd9acb48..3b7129f2 100644
--- a/LibationLauncher/LibationLauncher.csproj
+++ b/LibationLauncher/LibationLauncher.csproj
@@ -13,7 +13,7 @@
     <!-- <PublishSingleFile>true</PublishSingleFile> -->
     <RuntimeIdentifier>win-x64</RuntimeIdentifier>
 
-    <Version>4.4.0.63</Version>
+    <Version>4.4.0.64</Version>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/LibationLauncher/Program.cs b/LibationLauncher/Program.cs
index f63ca021..bc001ad6 100644
--- a/LibationLauncher/Program.cs
+++ b/LibationLauncher/Program.cs
@@ -30,7 +30,7 @@ namespace LibationLauncher
 
 			migrate_to_v4_0_0();
 			migrate_to_v4_0_3(); // add setting for whether to delete/retain aax
-			migrate_to_v5_x_x();
+			migrate_to_v5_0_0();
 
 			ensureLoggingConfig();
 			ensureSerilogConfig();
@@ -229,15 +229,19 @@ namespace LibationLauncher
 		}
 		#endregion
 
-		#region migrate_to_v5_x_x re-gegister device if device info not in settings
-		private static void migrate_to_v5_x_x()
+		#region migrate_to_v5_0_0 re-gegister device if device info not in settings
+		private static void migrate_to_v5_0_0()
 		{
 			if (!File.Exists(AudibleApiStorage.AccountsSettingsFile))
 				return;
 
 			var accountsPersister = AudibleApiStorage.GetAccountsSettingsPersister();
 
-			foreach (var account in accountsPersister?.AccountsSettings?.Accounts)
+			var accounts = accountsPersister?.AccountsSettings?.Accounts;
+			if (accounts is null)
+				return;
+
+			foreach (var account in accounts)
 			{
 				var identity = account?.IdentityTokens;
 
@@ -249,7 +253,7 @@ namespace LibationLauncher
 					!string.IsNullOrWhiteSpace(identity.AmazonAccountId))
 					continue;
 
-				var authorize = new AudibleApi.Authorization.Authorize(identity.Locale);
+				var authorize = new Authorize(identity.Locale);
 
 				try
 				{