This update is mostly a hotfix that fixes installation on Windows Server systems.
Get the Update
There are two releases of Paint.NET:
- Microsoft Store release (recommended)
- You can purchase it here. This helps fund development and is an alternative or supplement to sending in a donation. In addition, updates happen automatically in the background when you’re not using the app.
- If you already have it installed, the update should happen automatically once Microsoft certifies the update, usually within the next day or so. To get the update immediately (once it’s certified), you can follow the instructions listed here.
- Classic Desktop release
- Download the installer from the website. This is the recommended download if you don’t have Paint.NET installed. It can also be used to update the app.
- If you already have it installed, you should be offered the update automatically within the next few days, but you can also get it immediately by going to ⚙ Settings -> Updates -> Check Now.
- Offline Installers and Portable ZIPs are available over on GitHub.
Change Log
Changes since 5.1.3:
- Fixed: Installation on Windows Server will no longer fail with an error about a missing srclient DLL.
- Improved: When saving an image fails due to Windows Defender’s “Controlled Folder Access” setting, the error message will mention that instead of being a generic “I/O failure” message.
- New: GIF Comment metadata is now preserved. It maps to EXIF Photo.UserComment tags.
- Improved: Consolidated the number of threads used for Async Present from 3 per image (canvas, left ruler, top ruler) to 3 total.
- Improved: ColorManagementEffect now supports DxgiColorSpace color contexts (for plugin developers).
Paint.NET Blog 
I use Musescore 3 to notate music; up until this week I could paste graphic chord diagrams created in Paint.net into the title area of my score. I copy and paste the chord diagrams from .jpg files. Since updating Paint.net to 5.1.4 in the past week, I can still copy the diagrams within Paint.net, and also into MS Word, but they no longer paste into Musescore. The Musescore version has not changed and it has worked fine forever, so circumstantial evidence makes me think it’s something new in Paint.net. Any hope of fixing it?
Paint.net is awesome, by the way.
It looks like Musescore is still being actively developed/maintained, so you should raise this issue with them.
My guess is that it’s because PDN now only places a DIBv5 onto the clipboard, it does not also add a DIB (“DIBv1”), and Musescore is doing something wrong with that. Windows will synthesize the DIBv1 from the DIBv5, but maybe it’s doing in a way that Musescore doesn’t understand.