title: Maven and Eclipse Lift Project Errors
body: <p>I made a new project through the m2eclipse wizard and selected the blank liftweb archetype. The project was created and I added the scala nature to the project (I don't have the maven-scala plugin installed for the time being).</p>
  
  <p>I am able to run the project using the goal <code>jetty:run</code>. However, I still have the following errors showing up in eclipse (cleaning the project didn't do anything):</p>
  
  <pre class="lang-none prettyprint-override"><code>Description Resource    Path    Location    Type
  error while loading Helpers, Scala signature Helpers has wrong version  expected: 5.0  found: 4.1 in C:\Users\Ken\.m2\repository\net\liftweb\lift-webkit\0.8\lift-webkit-0.8.jar(net/liftweb/util/Helpers.class)    first       Unknown Scala Problem
  error while loading LiftRules, Scala signature LiftRules has wrong version  expected: 5.0  found: 4.1 in C:\Users\Ken\.m2\repository\net\liftweb\lift-webkit\0.8\lift-webkit-0.8.jar(net/liftweb/http/LiftRules.class)  first       Unknown Scala Problem
  error while loading Loc, Scala signature Loc has wrong version  expected: 5.0  found: 4.1 in C:\Users\Ken\.m2\repository\net\liftweb\lift-webkit\0.8\lift-webkit-0.8.jar(net/liftweb/sitemap/Loc.class) first       Unknown Scala Problem
  error while loading MainGenericRunner, Scala signature MainGenericRunner has wrong version  expected: 5.0  found: 4.1 in C:\Users\Ken\.m2\repository\org\scala-lang\scala-compiler\2.7.1\scala-compiler-2.7.1.jar(scala/tools/nsc/MainGenericRunner.class)  first       Unknown Scala Problem
  error while loading Menu, Scala signature Menu has wrong version  expected: 5.0  found: 4.1 in C:\Users\Ken\.m2\repository\net\liftweb\lift-webkit\0.8\lift-webkit-0.8.jar(net/liftweb/sitemap/Menu.class)  first       Unknown Scala Problem
  Plugin execution not covered by lifecycle configuration: org.scala-tools:maven-scala-plugin:2.15.2:compile (execution: default, phase: compile) pom.xml /first  line 76 Maven Project Build Lifecycle Mapping Problem
  Plugin execution not covered by lifecycle configuration: org.scala-tools:maven-scala-plugin:2.15.2:testCompile (execution: default, phase: test-compile)    pom.xml /first  line 76 Maven Project Build Lifecycle Mapping Problem
  </code></pre>
  
  <p>Here is a screenshot of the errors (may be easier to read, click the image for full size):</p>
  
  <p><a href="https://i.stack.imgur.com/0dgnB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/0dgnB.png" alt="Errors"></a></p>
  
  <p><strong>Does anybody know what is happening here? Any suggestions?</strong></p>
  
  <p>Additional information:</p>
  
  <p>The following warnings come up when I run the project:
  </p>
  
  <pre><code>[WARNING] 
  [WARNING] Some problems were encountered while building the effective model for com.kpthunder.lift:first:war:0.0.1-SNAPSHOT
  [WARNING] 'build.plugins.plugin.version' for org.mortbay.jetty:maven-jetty-plugin is missing. @ line 87, column 15
  [WARNING] 'build.plugins.plugin.version' for net.sf.alchim:yuicompressor-maven-plugin is missing. @ line 95, column 15
  [WARNING] 'build.plugins.plugin.version' for org.scala-tools:maven-scala-plugin is missing. @ line 72, column 15
  [WARNING] 'build.plugins.plugin.version' for org.apache.maven.plugins:maven-eclipse-plugin is missing. @ line 109, column 15
  [WARNING] 'reporting.plugins.plugin.version' for org.scala-tools:maven-scala-plugin is missing. @ line 133, column 15
  [WARNING] 
  [WARNING] It is highly recommended to fix these problems because they threaten the stability of your build.
  [WARNING] 
  [WARNING] For this reason, future Maven versions might no longer support building such malformed projects.
  [WARNING] 
  [WARNING] Using platform encoding (Cp1252 actually) to copy filtered resources, i.e. build is platform dependent!
  </code></pre>