I tried out the following example for CSE Getting Started - Client-side Extensions . No extensions from the example appears on the screen. Clicking on the My Custom Page, I have got the following error on the screen.
Failed to load extension: com.atlassian.myapp.bitbucket-plugin-template:extensionspagesmy-custom-page-extension.js
I did not find any error in the log of the running (local) server even I had the following logs about the found extensions