Hello Meghna,
I am afraid if you did not add it in any way, that it is your browser or even your operating system is throwing this pop-up, so outside of Mendix, so within mendix I am afraid you cannot fix it.
Can you share a screenshot of the pop up(s) and maybe your flow if you have one? Then the community can test for themselves and maybe find a solution!
Hi Meghna,
Download file activity cannot be modified. Instead there is a workaround for downloading the file using link. The below are the steps.
Note : This workaround is only verified in responsive web apps which runs in browser.
1. Create a nanoflow.
2. In your nanoflow construct an URL for the file. It should be similar to the below link.
syntax : {application root url}/file?guid={GUID of the file document}&name={your file name}
example : http://localhost:8084/file?guid=27303072740972657&name=indian-man-smiling-mockup-psd-cheerful-expression-closeup-portra.jpg
3. Pass the constructed url to open url activity.
The open Url activity will try to open the url, Since the url contains a file document it will be downloaded directly.
I hope this helps.