It's Opera the browser,to whom do you think should complain?? Stardock?? 

Well gee there Gaspershooters, ElanaAhova was looking for some help from the WinCustomize community.

If she wanted some Drama for her Opera she would have said so.

In any case, this sounds like some sort problem coming from some other software affecting Opera. 

1.  You may need to do a clean install.

2.  Windows 10 sometimes mis-behaves a bit when updates are pending install and thus causing interference with other programs.

Good luck getting it sorted.  I do not use Opera but maybe someone in the Community will see this and have some insight as to what is going on.

Do as Dave Bax suggests Elana. Chrome has no problem with downloading PDFs. I use Chrome exclusively because most other browsers, including FF, have problems with one thing or another, in my experience anyway. I once tried to dl a PDF for a friend to print it out. Downloading was no problem but opening it to print was one big headache. Edge couldn't handle it, nor IE (tried both), but Chrome breezed through it with no problem.