Refused to execute inline event handler because it violates CSP. (SANDBOX)
Answer for your non sandbox related question:
You have something in your code like this:
<button onclick="myFunction()">Click me</button>In a nutshell this is not allowed in chrome apps and extensions.
Change this to the following and it will work:
html:
<button id="myButton">Click me</button><script src="script.js"></script>script.js:
document.getElementById("myButton").addEventListener("click", myFunction);function myFunction(){ console.log('asd');}
Long story:
In chrome apps, Content Security Policy does not allow inline javascript. So you have to put your javascript in a .js file and include it in your HTML.
Further reading: https://developer.chrome.com/extensions/contentSecurityPolicy