Sonarqube: Custom Java Rules is Unable to analyze file

Hi SonarSourcer Team,

When I follow the Custom Java Rules guideline to develop a rule, and I want to execute the unit test, I get the following error:

Not only this custom rule, but also other rules provided in the java-custom-rules-example project, this error will also appear when I executing the unit test.

JDK Version: jdk-11.0.12
Sonarqube Version: 8.9.0.43852
SonarJava Version: 6.15.1.26025

Can someone help me?? Thanks alot