Although I love lombok, it gives too much problems while configuring sometimes, specially in Linux. When I was trying to install it, I was getting the following error:
Follow these steps:
- download lombok from https://projectlombok.org/download
 - double click on lombok.jar and specify the path of your ide and click install.
 - Restart your ide.
 - clean your project. If you are using eclipse or sts, click on Project->clean..
 
If you download the version of STS below and follow the set up. Lombok works with STS perfectly.
Version: 4.7.0.RELEASE Build Id: 202006181331
Copyright (c) 2007 - 2020 Pivotal, Inc. All rights reserved. Visit https://spring.io/tools
This product includes software developed by the Eclipse Foundation https://www.eclipse.org
This product includes software developed by the Apache Software Foundation https://www.apache.org
Lombok v1.18.12 "Envious Ferret" is installed. https://projectlombok.org/
I had this problem despite successfully installing lombok and restarting STS, so:
worked (as opposed to restarting it). See this: http://codeomitted.com/setup-lombok-with-stseclipse-based-ide/
Lombok not generating getter and setter STS
I have the same issue of lombok not working on STS. For me root cause was that I have spaces in my STS installation directory
-javaagent:E:\Installation Directory with spaces\sts-X.X\lombok.jar
in STS.iniand after changing it to relative path
-javaagent:lombok.jar
lombok started working.
It worked for me when I push the -javaagent arg to the top of the varargs list and restart the STS. By default Lombok adds this argument at the end in the ini file when you install.
Eg:
-vmargs
-javaagent:lombok.jar