I am also experiencing the same issue. The test case was created using Android, I keep getting the error message when trying to execute the test case.
java.lang.NoClassDefFoundError: com/kms/katalon/groovy/util/GroovyStringUtil
I am using a Windows 10 machine and Android v7.0 tablet.
Can you verify what version of Appium you’re using? For the best compatibility with Katalon Studio, you’ll need to use Appium server 1.8.1 (or Appium Desktop 1.6.3, which comes with the 1.8.1 server).
You can install Appium server using npm install -g appium@1.8.1 or Appium Desktop by finding an installer at: