title: Having issues with "Building web applications with Spring Boot and Kotlin" spring official documentation example
body: <h2><strong>Coding Environment</strong></h2>
  <ul>
  <li>Spring Tool Suite 4 <strong>4.3.2.RELEASE</strong></li>
  </ul>
  <ul>
  <li>Spring Boot <strong>2.3.1.RELEASE</strong></li>
  </ul>
  <ul>
  <li>Java <strong>1.8.0_171</strong></li>
  </ul>
  <ul>
  <li>Kotlin <strong>1.3.72</strong></li>
  </ul>
  <ul>
  <li>Kotlin Plugin for Eclipse <strong>0.8.20</strong></li>
  </ul>
  <ul>
  <li>Maven <strong>3.3.9</strong></li>
  </ul>
  <p>I wanted to convert my entire spring boot(<strong>Java</strong>) module to <strong>Kotlin</strong>. I was familiar with kotlin by going through kotlin documentation. I started spring boot with kotlin tutorial available at <a href="https://spring.io/guides/tutorials/spring-boot-kotlin/" rel="nofollow noreferrer">https://spring.io/guides/tutorials/spring-boot-kotlin/</a> by creating a new sample spring boot app wih Kotlin and Maven as build tool. Added only webmvc starter for simplicity. when i run the app without creating any <strong>@RestController</strong>'s or <strong>@Controller</strong>'s, the app is run successfully on specified port. after that i tried to add RestController(Controller also added,but same issue). then the issue came(thought it would work fine as it did in official sping boot with kotlin docs,but it did not.) and i found 2 consoles are active.</p>
  <ul>
  <li>Normal Console(where we check logs)</li>
  </ul>
  <ul>
  <li>JetBrains Console(<strong>org.jetbrains.kotlin.ui.console</strong>)</li>
  </ul>
  <p>with or without issue,the normal console is showing the logs like always it does i.e showing port number on which the app is run etc and jet brains console is blank(i.e no issues)
  but with the issue,jet brains console is showing the error</p>
  <p><strong>No Location<br/>
  EXCEPTION: java.lang.NoSuchMethodError: com.intellij.openapi.util.text.StringUtil.internEmptyString(Ljava/lang/String;)Ljava/lang/String;</strong></p>
  <p>googled it and got no solution for this  error. below are code snippets of Main Configuration and RestController classes.if any one faced this kind of issue,please help me solve this<br/></p>
  <h2><strong>KotlinDemoApplication.kt</strong></h2>
  <pre><code>@SpringBootApplication
  open class KotlinDemoApplication
  
  fun main(args: Array&lt;String&gt;) {
      runApplication&lt;KotlinDemoApplication&gt;(*args)
  }
  </code></pre>
  <h2><strong>GreetingController.kt</strong></h2>
  <pre><code>@RestController
  class GreetingController {
  
      @GetMapping(&quot;/greet&quot;)
      fun greet() = &quot;Kella Vivek&quot;
  }
  </code></pre>
  <p>your help or suggestion is very much appriciated.</p>