CRM 2015 Online, Quick View Form, JavaScript error

Hi,

In CRM 2015 Online, when I use a JavaScript to set a lookup field, the lookup field is set successfully. But

1. The related Quick View Form is NOT updated. That is kind of fine for me.

2. Even worse, when I close the form, there is a pop up message says '<Message>Unable to get property 'trim' of undefined or null reference</Message>'

If I remove the Quick View Form, the message will disappear.

Is there anyone have similar experience?
Dose anyone know how to fix the error? 

Thanks in advance.

Regards,

Zhenyu Wang