I am facing error when using scala eclipse maven GUI - eclipse

Question

I am facing error while using scala project in eclipse and maven, This is the project which I build from scratch , and it was working fine at that time.But now when I open it after a month it does show errors as shown in screenshots, even if i do mvn package it generates jar file as expected , But I see all my class files showing error at each line as shown in screen shot, what may be the problem?
I am using scala version: 2.10.6 and attached is below pom file.
scala.ide.org :
provider : scala-ide.org
plugin-name : scala2.10 jar
version ; 4.4.1201605041056
pligin-id: org.scala-ide.scala210.jars
<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.blogspot.whileonefork</groupId>
<artifactId>mvn-scala-trial1</artifactId>
<packaging>jar</packaging>
<version>1.0-SNAPSHOT</version>
<name>Sample Project for Blog</name>
<url>http://com.blogspot.whileonefork</url>
<properties>
<spark.version>1.6.0</spark.version>
</properties>
<!-- Notify Maven it can download things from here -->
<repositories>
<repository>
<id>scala-tools.org</id>
<name>Scala-tools Maven2 Repository</name>
<url>http://scala-tools.org/repo-releases</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>scala</id>
<name>Scala Tools</name>
<url>http://scala-tools.org/repo-releases/</url>
<releases>
<enabled>true</enabled>
</releases>
<snapshots>
<enabled>false</enabled>
</snapshots>
</pluginRepository>
</pluginRepositories>
<dependencies>
<!-- Scala version is very important. Luckily the plugin warns you if you don't specify:
[WARNING] you don't define org.scala-lang:scala-library as a dependency of the project -->
<dependency>
<groupId>org.scala-lang</groupId>
<artifactId>scala-library</artifactId>
<version>2.10.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/org.scalatest/scalatest_2.10 -->
<dependency>
<groupId>org.scalatest</groupId>
<artifactId>scalatest_2.10</artifactId>
<version>2.2.6</version>
</dependency>
<!-- MySQL -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.37</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-core_2.10</artifactId>
<version>${spark.version}</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-sql_2.10</artifactId>
<version>${spark.version}</version>
</dependency>
<dependency>
<groupId>org.apache.spark</groupId>
<artifactId>spark-hive_2.10</artifactId>
<version>${spark.version}</version>
</dependency>
<!-- SPARK CSV -->
<dependency>
<groupId>com.databricks</groupId>
<artifactId>spark-csv_2.10</artifactId>
<version>1.4.0</version>
</dependency>
</dependencies>
<build>
<!-- add the maven-scala-plugin to the toolchain -->
<plugins>
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<version>2.14.2</version>
</plugin>
<!-- adding here -->
<plugin>
<groupId>org.scala-tools</groupId>
<artifactId>maven-scala-plugin</artifactId>
<version>2.15.2</version>
<executions>
<execution>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>exec-maven-plugin</artifactId>
<version>1.1</version>
<configuration>
<mainClass>com.asharma.mainjob.main_job</mainClass>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-assembly-plugin</artifactId>
<version>2.4</version>
<configuration>
<descriptorRefs>
<descriptorRef>jar-with-dependencies</descriptorRef>
</descriptorRefs>
</configuration>
<executions>
<execution>
<id>assemble-all</id>
<phase>package</phase>
<goals>
<goal>single</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<!-- This plugin creates a single jar with all
the dependencies that are not already supplied by
the Spark runtime (scope 'provided'). -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-shade-plugin</artifactId>
<version>2.4</version>
</plugin>
<plugin>
<groupId>com.frugalmechanic</groupId>
<artifactId>scala-optparse</artifactId>
<version>1.1</version>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<mainClass>fully.qualified.MainClass</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
</plugins>
<pluginManagement>
<plugins>
<!--This plugin's configuration is used to store Eclipse m2e settings
only. It has no influence on the Maven build itself. -->
<plugin>
<groupId>org.eclipse.m2e</groupId>
<artifactId>lifecycle-mapping</artifactId>
<version>1.0.0</version>
<configuration>
<lifecycleMappingMetadata>
<pluginExecutions>
<pluginExecution>
<pluginExecutionFilter>
<groupId>
org.scala-tools
</groupId>
<artifactId>
maven-scala-plugin
</artifactId>
<versionRange>
[2.15.2,)
</versionRange>
<goals>
<goal>compile</goal>
<goal>testCompile</goal>
</goals>
</pluginExecutionFilter>
<action>
<ignore></ignore>
</action>
</pluginExecution>
</pluginExecutions>
</lifecycleMappingMetadata>
</configuration>
</plugin>
<plugin>
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-surefire-plugin</artifactId>
<configuration>
<forkMode>pertest</forkMode>
<argLine>-Xms256m -Xmx512m</argLine>
<testFailureIgnore>false</testFailureIgnore>
<skip>false</skip>
<includes>
<include>**/*IntegrationTestSuite.java</include>
</includes>
</configuration>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>