cannot add image

yesterday I still can add image. but now ca’t. I already try in 2 website

Dear maiyunanda
Thank you for your post. In order to find out the problem, we have tested the “add image” button of the Image Gallery plugin from our side. We tried it on Chrome, IE 11, Firefox, both on the 4.5.3 and on the 4.6 versions of the WordPress and it was working properly. Could you say, please what browser and which version of the WordPress are you using?
Thank you

I use wordpress 4.6 versions. and tried it on chrome Versi 52.0.2743.116 m (64-bit), and firefox 4.7

but also, when I activated this plugin, my widget cannot edit, cannot drag and drop or edit.

Dear maiyunanda
Thank you for answering the question. It seems that your issue is website specific. If it is now difficult for you, could you contact us via this page: https://huge-it.com/contact-us/ and we will try to solve your issue? In the meantime , while contacting us, give a try and change your current theme to another default WordPress theme and see if the issue persists, as there could be a conflict with the theme you currently run.
We will wait for your email.
Thank you!