I was facing this issue, while visiting http://localhost:4200 **'.

Then, when I opened up a web browser, I navigated to localhost:4200 and a web page with the following text were shown:

Error:  Cannot Get /

Solutions: This is related to most of time is incorrect syntax 

Step 1: open terminal and run "ng build"

Step 2: See the command output and you must find some syntax issue related to your code. Go ahead and fix your issue that problem will be gone