title: How to resolve issues with using external packages in IntelliJ?
body: <p>I recently switched from eclipse to Intellij and hence I am new new to it. Till a day before I was successfully able to compile my java program (maven) and generate output. The program uses multiple external packages and also Rserve to connect to R. However, when I tried to compile it today, it does not recognize any of the external packages and gives multiple errors like:</p>
  
  <pre><code>Error:(25, 26) java: package org.rosuda.REngine does not exist
  Error:(22, 53) java: package org.apache.commons.math3.optimization.fitting does not exist
  </code></pre>
  
  <p>On looking through the project structure, in the dependencies tab, it shows something like the following image. Can someone please help me finding the issue here? <img src="https://i.stack.imgur.com/3XRFS.png" alt="enter image description here"></p>
  
  <p><img src="https://i.stack.imgur.com/Iu90K.png" alt="enter image description here"></p>