Hi Rable - maybe try the following:
Add the following code to your index.html, just after the canvas element:
<div id="canvas-loader" style="background:url('https://cdnjs.cloudflare.com/ajax/libs/semantic-ui/0.16.1/images/loader-large.gif'); height:70px; width:70px; background-repeat:no-repeat; display:block; position:absolute; left:calc(50% - 35px); top:calc(50% - 35px)"></div>
Add the Browser object to your project, then add an On Start of Layout event, with the Execute JavaScript action.
Add the following code:
"document.getElementById('canvas-loader').style.cssText = 'display:none;'"
Haven't tested it, might work...