UserAgent: Mozilla/5.0 (Windows NT 10.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/66.0.3359.139 Safari/537.36

Steps to reproduce the problem:
1.It is random and does not reproduce on demand.
2. 
3. 

What is the expected behavior?
While viewing web pages rectangular black boxes will move around and pop up rnadomly on the page.  This has been happening on occassion for the past few days. 

What went wrong?
While viewing web pages rectangular black boxes will move around and pop up rnadomly on the page.  This has been happening on occassion for the past few days. 

Did this work before? N/A 

Chrome version: 66.0.3359.139  Channel: stable
OS Version: 10.0
Flash Version: Adobe 29