diff --git a/INSTALL.md b/INSTALL.md
index 57105f12a..38f593ebc 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -19,7 +19,7 @@
 You should be able to compile Aseprite successfully on the following
 platforms:
 
-* Windows 10 + [Visual Studio Community 2019 + Windows 10.0.18362.0 SDK](https://imgur.com/a/7zs51IT) (we don't support [MinGW](#mingw))
+* Windows 10 + [Visual Studio Community 2019 + Windows 10.0 SDK (the latest version available)](https://imgur.com/a/7zs51IT) (we don't support [MinGW](#mingw))
 * macOS 10.15.3 Catalina + Xcode 11.2.1 + macOS 10.15 SDK (older version might work)
 * Linux + gcc 9.2 or clang 9.0
 
diff --git a/data/strings/en.ini b/data/strings/en.ini
index e7a280e29..90bd4ae91 100644
--- a/data/strings/en.ini
+++ b/data/strings/en.ini
@@ -53,6 +53,7 @@ Import Sprite Sheet
 END
 error_loading_file = Error<<Error loading file: {0}||&OK
 error_saving_file = Error<<Error saving file: {0}||&OK
+file_format_doesnt_support_palette = Error<<Cannot save a color palette in {0} format||&OK
 export_animation_in_sequence = <<<END
 Notice
 <<Do you want to export the animation in {0} files?
diff --git a/src/app/app.cpp b/src/app/app.cpp
index ec1f84b13..805eb4bc2 100644
--- a/src/app/app.cpp
+++ b/src/app/app.cpp
@@ -303,7 +303,8 @@ int App::initialize(const AppOptions& options)
     ui::set_mouse_cursor_scale(preferences().cursor.cursorScale());
     ui::set_mouse_cursor(kArrowCursor);
 
-    ui::Manager::getDefault()->invalidate();
+    auto manager = ui::Manager::getDefault();
+    manager->invalidate();
 
     // Create the main window.
     m_mainWindow.reset(new MainWindow);
@@ -322,7 +323,16 @@ int App::initialize(const AppOptions& options)
     m_mainWindow->openWindow();
 
     // Redraw the whole screen.
-    ui::Manager::getDefault()->invalidate();
+    manager->invalidate();
+
+    // Pump some messages so we receive the first
+    // Manager::onNewDisplayConfiguration() and we known the manager
+    // initial size. This is required so if the OpenFileCommand
+    // (called when we're processing the CLI with OpenBatchOfFiles)
+    // shows a dialog to open a sequence of files, the dialog is
+    // centered correctly to the manager bounds.
+    ui::MessageLoop loop(manager);
+    loop.pumpMessages();
   }
 #endif  // ENABLE_UI
 
diff --git a/src/app/commands/cmd_save_palette.cpp b/src/app/commands/cmd_save_palette.cpp
index 05be7186d..893d697eb 100644
--- a/src/app/commands/cmd_save_palette.cpp
+++ b/src/app/commands/cmd_save_palette.cpp
@@ -1,4 +1,5 @@
 // Aseprite
+// Copyright (C) 2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -50,7 +51,7 @@ void SavePaletteCommand::onLoadParams(const Params& params)
   m_saveAsPreset = (params.get("saveAsPreset") == "true");
 }
 
-void SavePaletteCommand::onExecute(Context* context)
+void SavePaletteCommand::onExecute(Context* ctx)
 {
   const doc::Palette* palette = get_current_palette();
   std::string filename;
@@ -68,6 +69,18 @@ void SavePaletteCommand::onExecute(Context* context)
       return;
 
     filename = selFilename.front();
+
+    // Check that the file format supports saving indexed images/color
+    // palettes (e.g. if the user specified .jpg we should show that
+    // that file format is not supported to save color palettes)
+    if (!base::has_file_extension(filename, exts)) {
+      if (ctx->isUIAvailable()) {
+        ui::Alert::show(
+          fmt::format(Strings::alerts_file_format_doesnt_support_palette(),
+                      base::get_file_extension(filename)));
+      }
+      return;
+    }
   }
 
   if (!save_palette(filename.c_str(), palette, 16)) // TODO 16 should be configurable
@@ -75,7 +88,7 @@ void SavePaletteCommand::onExecute(Context* context)
 
   if (m_preset == get_default_palette_preset_name()) {
     set_default_palette(palette);
-    if (!context->activeDocument())
+    if (!ctx->activeDocument())
       set_current_palette(palette, false);
   }
   if (m_saveAsPreset) {
diff --git a/src/app/file/file.cpp b/src/app/file/file.cpp
index fa568235e..e7ed26bff 100644
--- a/src/app/file/file.cpp
+++ b/src/app/file/file.cpp
@@ -63,11 +63,13 @@ base::paths get_readable_extensions()
   return paths;
 }
 
-base::paths get_writable_extensions()
+base::paths get_writable_extensions(const int requiredFormatFlag)
 {
   base::paths paths;
   for (const FileFormat* format : *FileFormatsManager::instance()) {
-    if (format->support(FILE_SUPPORT_SAVE))
+    if (format->support(FILE_SUPPORT_SAVE) &&
+        (requiredFormatFlag == 0 ||
+         format->support(requiredFormatFlag)))
       format->getExtensions(paths);
   }
   return paths;
diff --git a/src/app/file/file.h b/src/app/file/file.h
index 526280cf0..9e9385a7b 100644
--- a/src/app/file/file.h
+++ b/src/app/file/file.h
@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2018-2020  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -281,7 +281,7 @@ namespace app {
 
   // Available extensions for each load/save operation.
   base::paths get_readable_extensions();
-  base::paths get_writable_extensions();
+  base::paths get_writable_extensions(const int requiredFormatFlag = 0);
 
   // High-level routines to load/save documents.
   Doc* load_document(Context* context, const std::string& filename);
diff --git a/src/app/file/jpeg_format.cpp b/src/app/file/jpeg_format.cpp
index 4abde1853..274417b4e 100644
--- a/src/app/file/jpeg_format.cpp
+++ b/src/app/file/jpeg_format.cpp
@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2018-2020  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -357,7 +357,9 @@ bool JpegFormat::onSave(FileOp* fop)
   JSAMPARRAY buffer;
   JDIMENSION buffer_height;
   const auto jpeg_options = std::static_pointer_cast<JpegOptions>(fop->formatOptions());
-  const int qualityValue = (int)base::clamp(100.0f * jpeg_options->quality, 0.f, 100.f);
+  const int qualityValue =
+    (jpeg_options ? (int)base::clamp(100.0f * jpeg_options->quality, 0.f, 100.f):
+                    100);
 
   int c;
 
diff --git a/src/app/file/palette_file.cpp b/src/app/file/palette_file.cpp
index 2ae17a674..5ebd8faf3 100644
--- a/src/app/file/palette_file.cpp
+++ b/src/app/file/palette_file.cpp
@@ -1,5 +1,5 @@
 // Aseprite
-// Copyright (C) 2018-2019  Igara Studio S.A.
+// Copyright (C) 2018-2021  Igara Studio S.A.
 // Copyright (C) 2001-2018  David Capello
 //
 // This program is distributed under the terms of
@@ -47,7 +47,7 @@ base::paths get_readable_palette_extensions()
 
 base::paths get_writable_palette_extensions()
 {
-  base::paths paths = get_writable_extensions();
+  base::paths paths = get_writable_extensions(FILE_SUPPORT_INDEXED);
   for (const char* s : palExts)
     paths.push_back(s);
   return paths;
diff --git a/src/ui/manager.cpp b/src/ui/manager.cpp
index 4737d3f62..2106d3a4e 100644
--- a/src/ui/manager.cpp
+++ b/src/ui/manager.cpp
@@ -284,7 +284,7 @@ void Manager::run()
   if (first_time) {
     first_time = false;
 
-    Manager::getDefault()->invalidate();
+    invalidate();
     set_mouse_cursor(kArrowCursor);
   }