New: Completely redone high-res icons throughout the app which match the Microsoft Office style guidelines, with native support for up to 400% scaling (384 DPI)
New: File -> Save All (thanks @Bruce Bowyer-Smyth!)
New: Turkish language
New: Move Layer commands are now present in the Layers menu, not just on the Layers window
New: Layers -> Rotate 180 (thanks @null54!)
New: Plugins can now use the UIScaleFactor class, which simplifies making decisions about DPI and scaling
Improved: Image thumbnail list at the top of the main window now reacts to horizontal mouse wheel or trackpad swiping
Improved: The Text Tool's "Font Size Metric" button now has a tooltip explaining it
Improved: When many images are open, Paint.NET now closes significantly faster (thanks @Bruce Bowyer-Smyth for the fix!)
Improved: File -> Open Recent now has up to 10 images (up from 8 )
Changed: Ctrl+Shift+F6 and +F7 will now also reset the floating window sizes for History and Layers, respectively (same if you Ctrl+Shift+Click on the button at the top-right of the main window)
Changed: (for plugins) EffectFlags.SingleRenderCall is deprecated. Plugins should use the new EffectRenderingSchedule.None option instead.
Changed: Settings -> Plugin Errors now shows up even if there are no plugin errors. This ensures consistency, especially with the newly asynchronous nature of plugin loading (otherwise there's no way to distinguish "no errors" from "not done loading plugins").
Fixed: Items in the File -> Open Recent menu will no longer get bigger or smaller when moving between monitors with different DPIs
Fixed: An icon handle was being leaked every time a dialog was opened (thanks @null54 for the fix!)
Fixed a crash when running GPU effects (e.g. Black & White) on very large, very tall images
Fixed: "Bad" plugins can no longer ruin the undo system by rendering outside of the selection