diff --git a/res/appstore/Package.appxmanifest b/res/appstore/Package.appxmanifest
index 7523f49c..5d896c1d 100644
--- a/res/appstore/Package.appxmanifest
+++ b/res/appstore/Package.appxmanifest
@@ -11,7 +11,7 @@
   <Identity
     Name="19453.net.Rufus"
     Publisher="CN=7AC86D13-3E5A-491A-ADD5-80095C212740"
-    Version="3.16.1820.0" />
+    Version="3.16.1821.0" />
 
   <Properties>
     <DisplayName>Rufus</DisplayName>
diff --git a/src/format.c b/src/format.c
index 8e68ae3d..17c8123b 100644
--- a/src/format.c
+++ b/src/format.c
@@ -739,10 +739,12 @@ static BOOL ClearMBRGPT(HANDLE hPhysicalDrive, LONGLONG DiskSize, DWORD SectorSi
 		goto out;
 	CHECK_FOR_USER_CANCEL;
 	liFilePointer.QuadPart = DiskSize - (LONGLONG)SectorSize * MAX_SECTORS_TO_CLEAR;
-	SetFilePointerEx(hPhysicalDrive, liFilePointer, &liFilePointer, FILE_BEGIN);
 	// Windows seems to be an ass about keeping a lock on a backup GPT,
 	// so we try to be lenient about not being able to clear it.
-	WriteFileWithRetry(hPhysicalDrive, pZeroBuf, SectorSize * MAX_SECTORS_TO_CLEAR, NULL, WRITE_RETRIES);
+	if (SetFilePointerEx(hPhysicalDrive, liFilePointer, &liFilePointer, FILE_BEGIN)) {
+		IGNORE_RETVAL(WriteFileWithRetry(hPhysicalDrive, pZeroBuf,
+			SectorSize * MAX_SECTORS_TO_CLEAR, NULL, WRITE_RETRIES));
+	}
 	r = TRUE;
 
 out:
diff --git a/src/iso.c b/src/iso.c
index 53c171f9..35e3d494 100644
--- a/src/iso.c
+++ b/src/iso.c
@@ -894,7 +894,7 @@ BOOL ExtractISO(const char* src_iso, const char* dest_dir, BOOL scan)
 	p_udf = udf_open(src_iso);
 	if (p_udf == NULL)
 		goto try_iso;
-	uprintf("%sImage is an UDF image", spacing);
+	uprintf("%sImage is a UDF image", spacing);
 
 	p_udf_root = udf_get_root(p_udf, true, 0);
 	if (p_udf_root == NULL) {
diff --git a/src/rufus.c b/src/rufus.c
index a31fa56b..f4b7d468 100755
--- a/src/rufus.c
+++ b/src/rufus.c
@@ -72,6 +72,7 @@ static BOOL user_notified = FALSE;
 static BOOL relaunch = FALSE;
 static BOOL dont_display_image_name = FALSE;
 static BOOL user_changed_label = FALSE;
+static BOOL user_deleted_rufus_dir = FALSE;
 static BOOL app_changed_label = FALSE;
 static BOOL allowed_filesystem[FS_MAX] = { 0 };
 static int64_t last_iso_blocking_status;
@@ -2217,11 +2218,13 @@ static INT_PTR CALLBACK MainCallback(HWND hDlg, UINT message, WPARAM wParam, LPA
 
 			// Save the current log to %LocalAppData%\Rufus\rufus.log
 			log_size = GetWindowTextLengthU(hLog);
-			if ((log_size > 0) && ((log_buffer = (char*)malloc(log_size)) != NULL)) {
+			if ((!user_deleted_rufus_dir) && (log_size > 0) && ((log_buffer = (char*)malloc(log_size)) != NULL)) {
 				log_size = GetDlgItemTextU(hLogDialog, IDC_LOG_EDIT, log_buffer, log_size);
 				if (log_size-- > 1) {
-					static_sprintf(tmp, "%s\\%s\\rufus.log", app_data_dir, FILES_DIR);
-					FileIO(TRUE, tmp, &log_buffer, &log_size);
+					IGNORE_RETVAL(_chdirU(app_data_dir));
+					IGNORE_RETVAL(_mkdir(FILES_DIR));
+					IGNORE_RETVAL(_chdir(FILES_DIR));
+					FileIO(TRUE, "rufus.log", &log_buffer, &log_size);
 				}
 				safe_free(log_buffer);
 			}
@@ -3669,11 +3672,12 @@ relaunch:
 					CyclePort(index);
 				continue;
 			}
-			// Alt-D => Delete the 'rufus_files' subdirectory
+			// Alt-D => Delete the subdirectory where Rufus keeps its files
 			if ((msg.message == WM_SYSKEYDOWN) && (msg.wParam == 'D')) {
 				static_sprintf(tmp_path, "%s\\%s", app_data_dir, FILES_DIR);
-				PrintStatus(STATUS_MSG_TIMEOUT, MSG_264, tmp_path);
+				PrintStatusDebug(STATUS_MSG_TIMEOUT, MSG_264, tmp_path);
 				SHDeleteDirectoryExU(NULL, tmp_path, FOF_SILENT | FOF_NOERRORUI | FOF_NOCONFIRMATION);
+				user_deleted_rufus_dir = TRUE;
 				continue;
 			}
 			// Alt-E => Enhanced installation mode (allow dual UEFI/BIOS mode and FAT32 for Windows)
diff --git a/src/rufus.rc b/src/rufus.rc
index 451f52e1..1512e560 100644
--- a/src/rufus.rc
+++ b/src/rufus.rc
@@ -33,7 +33,7 @@ LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL
 IDD_DIALOG DIALOGEX 12, 12, 232, 326
 STYLE DS_SETFONT | DS_MODALFRAME | DS_CENTER | WS_MINIMIZEBOX | WS_POPUP | WS_CAPTION | WS_SYSMENU
 EXSTYLE WS_EX_ACCEPTFILES
-CAPTION "Rufus 3.16.1820"
+CAPTION "Rufus 3.16.1821"
 FONT 9, "Segoe UI Symbol", 400, 0, 0x0
 BEGIN
     LTEXT           "Drive Properties",IDS_DRIVE_PROPERTIES_TXT,8,6,53,12,NOT WS_GROUP
@@ -395,8 +395,8 @@ END
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 3,16,1820,0
- PRODUCTVERSION 3,16,1820,0
+ FILEVERSION 3,16,1821,0
+ PRODUCTVERSION 3,16,1821,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -414,13 +414,13 @@ BEGIN
             VALUE "Comments", "https://rufus.ie"
             VALUE "CompanyName", "Akeo Consulting"
             VALUE "FileDescription", "Rufus"
-            VALUE "FileVersion", "3.16.1820"
+            VALUE "FileVersion", "3.16.1821"
             VALUE "InternalName", "Rufus"
             VALUE "LegalCopyright", "© 2011-2021 Pete Batard (GPL v3)"
             VALUE "LegalTrademarks", "https://www.gnu.org/licenses/gpl-3.0.html"
             VALUE "OriginalFilename", "rufus-3.16.exe"
             VALUE "ProductName", "Rufus"
-            VALUE "ProductVersion", "3.16.1820"
+            VALUE "ProductVersion", "3.16.1821"
         END
     END
     BLOCK "VarFileInfo"