Krpano reports picture loading failed but in the browser it works well

I write the code to toggle pictures between two images. The code is as follows:

    <action name="switchRotation">

set(layer[skin_autorotate].url, calc(autorotate.enabled ? "skin/rotate.png" : "skin/pause.png"));

set(autorotate.enabled, calc(autorotate.enabled ? false : true));

    </action>

<layer name="skin_autorotate" style="skin_base|skin_glow" url="pause.png" align="right" x="130" y="0" scale="0.45" onclick="switchRotation()"/>

And krpano Tools reports: ERROR: plugin[skin_autorotate] - loading of "skin/rotate.png" failed!

But starting the testingserver to run the scene, it works well.

So is there a solution?

And my krpano version is 1.20.7, Whether the issue is related to the software version?

The problem solved, thanks a lot!