After successfully reloading data with Reload Button, app occurs unknown error

[wanyunyang]

I installed a Reload Button from https://github.com/mhamano/Qlik-Sense-Reload-Button, which allows user to reload data by clicking on this button. But every time after successfully reloading data with Reload Button, app will occur "unknown error" within couple seconds. Any idea why this happens?

Thanks in advance!