Widget Button problem

I like to generate a simple widget button with:

<div ng-init= "testInit = {'name': 'test', 'type': 'button', 'action_type': 'navigate', 'navigate_dashboard': 'home', 'iconset': 'custom-icon', 'icon': 'control_building_empty', 'icon_size': 80,  'icon_replacestext': true}"/>
<widget-button  ng-model="testInit"/>

I put the new SVG Icon to the “icons/classic” folder

However when I do a preview of the Button I see for a split second the correct Icon but then it changes back to this:

Whats wrong, can someone help me?

hmm now I upgraded to 2.5M5 and now in the log files once I click Preview in the widget I get those errors:
[org.eclipse.jetty.http.HttpParser ] - URI is too large >8192

Can you please open the Chrome dev tools, go to Network tab, switch to the preview and report back what you see?

hmm strange I solved by restarting the docker container and using a fresh folder for the userdata and conf folder. Now it works…