Mozilla not allowing to install addon from sites after updating to version 43.0

Hi,
We are using Firefox as our default browser across our organization.
We have developed Mozilla Add-on Firefox which will be used by users within our company.
After updating Mozilla Firefox to version 43.0 Mozilla browser restricts to install add-on from our intranet web application. It shows message “Firefox prevented this site from asking you to install software on your computer”.
We are installing the add-on in Mozilla Browser by accessing URL in following format:
http://doaminname/appname/addname.xpi

Please guide us here.
We really appreciate your help.

This question has been answered many times already. For example here.

Thanks Andreas, we know this steps but is there another way to do this because we have to make this changes on each users machine within our organization and there is more than 200 users. Is there any another way to do?
We really appreciate your help.

I don’t know of any way.