examples don't run
example demos don't run

To Reproduce
Steps to reproduce the behavior:
1. Go to 'examples' folder
2. Click on demos 2, 4, 6, 7, 8

Expected behavior
demos don't run.

If applicable, add screenshots to help explain your problem.
![image](https://user-images.githubusercontent.com/35934791/68529136-c6eef600-0314-11ea-8571-5aea7f1ce39e.png)
![image](https://user-images.githubusercontent.com/35934791/68529156-20572500-0315-11ea-90d2-6e4aaac3a6fe.png)
![image](https://user-images.githubusercontent.com/35934791/68529166-2f3dd780-0315-11ea-9ca5-69ec39fb07ee.png)
![image](https://user-images.githubusercontent.com/35934791/68529178-3bc23000-0315-11ea-9afa-51ced4977688.png)
![image](https://user-images.githubusercontent.com/35934791/68529186-4977b580-0315-11ea-85f7-8cb065978c7f.png)

Desktop:
 - OS: 10.0.18362.418
 - Browser chrome
 - Version 1.0.2


**Additional context**
they don't run for different reasons. 