NEVER put an "alien" source in your trusted list, especially in a secure environment such as your QuickBooks financial program; otherwise, your system can be susceptible to a Cross-Site Scripting (XSS) Attack. In other words, the JS or HTML file being referenced could contain malicious or data-extracting code.

The steps below will show you how to customize the Internet Explorer browser to BLOCK optimizely DOT COM and to effectively remove script errors from that source:

1. Close QuickBooks.
2. Open Internet Explorer.
3. From the Command Bar, select Tools.
4. Select Internet Options, then select the Security tab.
5. Click Restricted Sites and click on Sites. 
6. In the Add, this website to the zone field, type in *.optimizely.com and click on Add.
7. Click on Close.
8. Click on OK.
9. Close Internet Explorer.
10. Open QuickBooks.