JavascriptException: Javascript error (Warning: The server did not provide any stacktrace information)

During execution via IE, you might encounter the following error:

Error opening Salesforce UI Connection. Connection Name: HC_Portal_User, cause: JavascriptException: JavaScript error (WARNING: The server did not provide any stacktrace information]

This error appears because of Javascript is not enabled in your Internet Explorer. You can resolve this error by enabling Javascript on your IE browser.
Follow the steps below to enable Javascript on IE:
1. Click the gear icon/Tools menu to the right of the Internet Explorer address bar.
2. Select Internet Options from the drop-down menu.
3. Select the Security tab at the top of the dialog box.
4. Select the earth (Internet) icon.
5. Select the Custom Level button under the Security level for this zone section.
6. Locate the Scripting section within the list.
7. Under Active Scripting, select Enable, then hit OK.
8. Answer yes to the following conformation box.
9. Hit OK to close the Internet Options window.

Then retry execution of test cases on IE to check that the error is resolved.