https://www.revenue.wi.gov/forms/2015...
I tried on my laptop (Windows 7) that worked. I thought I needed to upload more documents than just the 1040... hence my using my desktop which is hooked into my scanner (cord placement makes it very difficult to hook my laptop to the scanner). I have Adobe Reader DC on both my PC (Windows 10) and my laptop (Windows 7). I don't know if I have trouble with the DC on my laptop as the link works online.
I do have IE, Firefox and Chrome on both computers... well, actually it isn't IE, it's Microsoft Edge. I tried all 3 browsers. I did discover that other PDFs on Windows 10 allows for the attachment. It was just the tax return for some reason. The tax return is grayed out, but I can attache files to my other PDFs that I open. (I don't think the file attachment location in the commenting part is as user friendly as Reader XI, X, etc, but that is personal preference).
Anyway, I got what I needed to done... but for some reason I'm having difficulties with it with Windows 10. And yes, I did make sure I have the extensions loaded in my browsers.
Thank you