A user on the same computer goes between two different SP 2013 environments. When clicking "Download a copy" on a document item in one environment, Internet Explorer asks "Do you want to open or save [File Name] from [Domain Name]?" Clicking this same button in a different environment prompts Internet Explorer to ask "Do you want to save [File Name] from [Domain Name]?" with no option to just open.
What do I need to change in the second environment to allow the open as well as save option?
Try this in non-working environment IE
Tools > Internet Options > Advanced tab > scroll down to Security > you will find an option "Do not save encrypted pages to disk". Take the checkmark out and that should fix this immediately (no need to restart IE or reload the page)
Refer here
I resolved this by going to Central Admin -> Manage Web Applications, clicking the web application row, then General Settings from the top ribbon, and setting Browser File Handling from "Strict" to "Permissive".
