Why does change from Spring boot version 2.1.4 to 2.1.5 gives unknown configuration Maven error?

According to this link you can fix the issue by downgrading the maven-jar-plugin to 3.1.1 (from 3.1.2). I can confirm that the fix works for my own projects.

Add the following entry to your pom to fix that issue.

<properties>
    <maven-jar-plugin.version>3.1.1</maven-jar-plugin.version>
</properties>

An official bug entry for eclipse exists as well.