[ERROR] Error executing Maven. [ERROR] 1 problem was encountered while building the effective set

<profile>
		<id>jdk-1.8</id>
		<activation>
			<activeByDefault>true</activeByDefault>
			<jdk>1.8</jdk>
		</activation>
		<properties>
			<maven.compiler.source>1.8</maven.compiler.source>
			<maven.compiler.source>1.8</maven.compiler.source>
			<maven.compiler.compilerVersion>1.8</maven.compiler.compilerVersion>
		</properties>
	</profile>