BUG; IE is not loading/running selected test cases in Katalon

Katalon Studio
Version: 5.1.0
Build: 2
Katalon Studio is up to date.
Copyright KMS Technology
https://www.katalon.com

Execute any test case in Firefox, Chrome or IE11
Firefox & Chrome work as expected

IE11 results in the following error:
Content from Windows …:\Katalon Studio Windows 64…\config.metadata.log
Warning: NLS unused message: Key in: com.kms.katalon.composer.webui.constants.composerWebuiMessages
Warning: NLS missing message: DIA_CONFIRM_INSTALL_WEBDRIVER in: com.kms.katalon.composer.webui.constants.composerWebuiMessages
Warning: NLS missing message: DIA_CONFIRM_INSTALL_WEBDRIVER_TITLE in: com.kms.katalon.composer.webui.constants.composerWebuiMessages