FAILED because (of) Variable 'selenium' is not defined for test case

Hello everyone!

This is my first post here so tell me if I missed anything!

I’ve previously used Selenium IDE to create some test case and now I’m trying to import them into Katalon Studio.
I used the import in katalon recorder with the format ‘Katalon Studio’
When I try to run my test in katalon studio, I have this error.
FAILED because (of) Variable ‘selenium’ is not defined for test case.

I’ve noticed that one of my import is crossed :

import com.thoughtworks.selenium.Selenium
This element has neither attached source or javadoc, hence no javadoc could be found.

Do I need to import more library or something?

Thanks in advance for your answers!
And nice to meet you all!

katalonImport.txt

Hello
I don’t know you convert Selenium IDE to Katalon,
I think better you write new TC in Katalon Studio

By content alone, Not find correct problem
Maybe somewhere used variable selenium

Thanks for the answers jyk, I found the solution!