The pom.xml maybe its missing any artifact(s)?
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.multichainjavaapi</groupId> <artifactId>MultiChainJavaAPI</artifactId> <version>0.4.17-SNAPSHOT</version> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <java.version>1.8</java.version> <maven-compiler-plugin.version>3.1</maven-compiler-plugin.version> <xmlrpc-client.version>3.1.3</xmlrpc-client.version> <httpclient.version>4.3.6</httpclient.version> <gson.version>2.8.1</gson.version> <commons-codec.version>1.10</commons-codec.version> <commons-collections4.version>4.1</commons-collections4.version> </properties> <scm> <connection>scm:git:git://github.com/SimplyUb/MultiChainJavaAPI.git</connection> <developerConnection>scm:git:[email protected]/SimplyUb/MultiChainJavaAPI.git</developerConnection> <url>https://github.com/SimplyUb/MultiChainJavaAPI</url> </scm> <build> <plugins> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>${maven-compiler-plugin.version}</version> <configuration> <source>${java.version}</source> <target>${java.version}</target> </configuration> </plugin> <plugin> <artifactId>maven-assembly-plugin</artifactId> <executions> <execution> <phase>package</phase> <goals> <goal>single</goal> </goals> </execution> </executions> <configuration> <descriptorRefs> <descriptorRef>jar-with-dependencies</descriptorRef> </descriptorRefs> </configuration> </plugin> </plugins> </build> <dependencies> <dependency> <groupId>org.apache.xmlrpc</groupId> <artifactId>xmlrpc-client</artifactId> <version>${xmlrpc-client.version}</version> </dependency> <dependency> <groupId>org.apache.httpcomponents</groupId> <artifactId>httpclient</artifactId> <version>${httpclient.version}</version> </dependency> <dependency> <groupId>com.google.code.gson</groupId> <artifactId>gson</artifactId> <version>${gson.version}</version> </dependency> <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>${commons-codec.version}</version> </dependency> <dependency> <groupId>org.apache.commons</groupId> <artifactId>commons-collections4</artifactId> <version>${commons-collections4.version}</version> </dependency> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> <scope>test</scope> </dependency> </dependencies> </project>