IntelliJ lombok plugin isn't compatible
2020 Edit: Try uninstalling and reinstalling the Lombok plugin.
It's a temporary issue. The github issue below says others have had luck uninstalling / reinstalling the plugin.
https://github.com/mplushnikov/lombok-intellij-plugin/issues/775
If that does not work then there is a plugin you can install manually as a workaround.
Edit: Here are some screenshots on uninstalling/reinstalling.
Go to settings -> plugins, search for lombok under intalled. Click on the dropdown menu to show 'Uninstall'.
Click 'apply', go to the marketplace tab and click install. Then restart your IDE.
I just updated the intellij dependency and build it locally. For me this lombok-plugin-0.30-EAP.zip works until the official update ist out :-) (Settings➙Plugins➙⚙️➙Install Plugin from Disk...)