It seems the repository has not been announced for the project you want to use with the sonar plugin. Perhaps you have configured repositories for buildscript or only for other projects (in your assembly of multiprojects?)
To enable sonar, you need to set up a repository where it can be enabled. You can have a corporate repository in your company, or you can use public ones, for example, mavencentral or bintray. declare, for example, a jcenter repository to resolve sonar. just add the following to your build script:
repositories { jcenter() }
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