I created a patcher, that disables checksum checking on ironman game starting or loading. That means that use can use any mods you want and still earning achievements.

1. Download latest patcher executable from GitHub releases page[github.com]
2. Unzip it in directory with eu5.exe executable file (right-click on EU5 on steam > Manage > Browse local files > Go in binaries directory)
3. Run universal-checksum-patcher-windows.exe

1. Can I get banned for using that patcher?
I can't guarantee you won't. Maybe.

2. Can my PC get hacked by using this patcher?
I can't guarantee you won't. Maybe.

3. Patch can't apply
Most probably Paradox major update changed bytes pattern, and now I need to recalculate hex values. All you can do is wait and pray.

4. Can I get achievements in multiplayer?
No.

5. Can I connect to players with other checksum in multiplayer?
No.

My patcher is based on Stellaris guide on same theme, I just automated patching process, so I give a huge respect to original author.
My guides for other Paradox games:
Europa Universalis IV - link
Hearts of Iron IV - link

GitHub - https://github.com/IlliaYalovoi/universal-checksum-patcher