After opening Acrobat Reader DC (in a windowed mode, not in tabbed), it, for some mysterious reason, switches off the Windows 10 Explorer setting for windows to cast shadows. It results in focused folder windows becoming visually borderless, making it very difficult to work with them.
The problem was described here for Acrobat DC:
https://acrobat.uservoice.com/forums/590923-acrobat-for-windows-and-mac/suggestions/38822896-bug-shadows-disappear-on-windows-10-explorer-wind
but it fully (and even more irritably) applies to Acrobat Reader DC, too.

It seems that for some reason, Acrobat Reader changes (switches off) each time the inherent Windows setting which can be found in System > Visual Effects tab > Show shadows under windows checkbox.

The problem persist already for a long time, please fix it!

I have problem when PDF document is stored at network drive and my notebook has temporary problem with WiFi. Or when notebook is suspended and later resumed, network drive is not accessible for some time (I have to reconnect it manually). In such cases I see many blank pages in PDF file that was opened in the past (new pages are not read from the file). I have to close document and open it again. That is not nice and I believe that "refresh/reload" function will fix this problem. It is possible to find similar requests in the forums on Internet.

Other use is for users who create their own PDF files, like printing to PDF file, so PDF file is changing on their drive.

Currently, click-hold and dragging with the middle mouse button results (hand symbol with four arrows) in the document scrolling at a (rather extreme) rate of speed that is determined how far away your cursor is from where you first clicked the button. The document will scroll continuously until you either move your cursor back closer to its initial location, or release the mouse button.
I would much prefer the behavior to be like what you get when you hold space and then click and drag with the left mouse button. I.e., you "drag" the document around with the mouse, and the document only moves as much as you "drag" it.

Please implement this behavior !
Thank you.

I have to work with PDFs a lot and I have to deal with them via browser. For the past years I haven't had any problems with using the browser PDF-viewer, but as of recently the option to do a quick google search in a new tab when highlighting text within a document and right-clicking on it is no longer available. There is 'copy', 'print', 'rotate', 'save as' but not the 'search the web for [highlighted text]' which was so very helpful and useful for me. Please, consider making it available again since I can hardly imagine how anyone would benefit from removing this feature.

Please for goodness' sake give users the option to completely remove the left and right sidebars instead of merely collapsing them. For users using Reader, the vast majority of the time all they will want to do is only read a PDF, and many will want as much screen space as possible to do so.

For the average Reader user, in the left toolbar the only thing they may want is thumbnail or chapter view. This could be on the top toolbar, with the other options available on a drop down menu from that button if you really must keep them there. The right toolbar, meanwhile, is completely redundant with the "Tools" pane. Being made up of options for creating and editing, these merely get in the way for Reader users who just want to read. The collapsed bar can easily be clicked mistakenly when attempting to scroll, and when a PDF hides the scrollbar (which there doesn't seem to be an easy way to either disable or re-enable), the collapsed bar will likely be mistaken for the scrollbar period.

I understand that these are considered 'features', but for many users they are merely an inconvenience. In many, many other programs, side toolbars are dockable and can be moved or closed. There are so many other options on how it could've been implemented that aren't so aggravating. Please either use one, or give users the option to completely disable them.

Many PDF documents contain internal links. When clicking on these, the user is taken to another part of the document. It would be incredibly useful to me and my colleagues if there was a 'preview link' option. Perhaps this could work by hovering the mouse over the link, and the preview to the link pops up in a small temporary window, allowing you to quickly view the link, without redirecting to a different page.

The motivation for this is as follows: In mathematical sciences, these internal links often refer to equations earlier in the document, which are being combined to create new results. It can be difficult and frustrating to constantly scroll up and down, to check a calculation, and I often lose my place. This would be the digital equivalent of having two book pages open at the same time, and would make checking calculations so much easier!

1. Open the attached document, which is a dishwasher manual, in Acrobat reader, and search for the word "floor". It will not be found. However, it's present in the document on page 6 in the bottom of the left column.

2. In Reader, go to the page 6 and copy to clipboard the line beginning with "When the GREEN LIGHT"'; then open Notepad and paste. You will see the space in the middle of the word "floor".

So it looks like the text has a space in the middle, although the word appears in Reader without the space. This makes more difficult text operations and search.