Adobe Acrobat Reader DC Suddenly Not Opening

I have the same problem with a Windows 11 computer (64 bit). Suddenly Acrobat Reader can't open in Protected Mode because it is "Incompatible with Windows Configuration" It can't open with Protected Mode Disabled either.

I was going crazy with this today after trying to launch Acrobat DC for the first time after setting up my new 2020 iMac. Photoshop, Illustrator, etc. opened with no problem, but for some reason Acrobat would not launch. (It was NOT that is was off-screen as some have found; the little dot under open applications in the dock was not there, so the application was NOT open.) I poked around in my files...tried an Uninstall app there; tried removing preference files...nothing. Finally, I tried Uninstall in the Creative Cloud list of Adobe applications, and then Install, and that worked.

I've got the same problem in Windows 10 that started today. I do get an error message:-

Windows cannot find C:\Program Files (x86)\Adobe\Acrobat Reader DC\Reader\AcroRd32.exe make sure you've typed the name correctly.

The file is there, the spelling is OK, I've tried starting from there with the same result. Compatibility mode in 8 or 7 doesn't work either. I've uninstalled, rebooted and reinstalled, no effect. Ditto cascading windows, etc.

I use AVG and do get a message saying that Acrobat REader had woken up but there's nothing on screen anywhere.

Any ideas or do I revert to the Google reader?

This is not working for me any other ideas?

In Safari make sure that pop up windows are enabled and Adobe plug in is also enabled for the site.

Wowzer, this had me pulling my hair out. I'm on macOS on a MacBook Pro and no amount of uninstalling, re-installing, updating or playing with preferences fixed this...I had even used the various Window tips to see if that would do the trick (as I sometimes have an external display).

The true fix required both of the suggestions above and then some:

1. I signed out of Adobe Creative Cloud (the app), and then;
2. Close the Acrobat Pro DC app
3. Delete the plist noted above
4. Re-open the app
5. Open a PDF
6. Use Window -> Cascade

It's also worth noting that I may have had plain old Adobe Reader originally, but had then gotten a license for Acrobat Pro DC. I had also been getting errors when trying to use the Help -> Sign-in/sign-out option.

After this, I double-checked Finder for the new plist file and I don't have what was noted above, instead now I have "com.adobe.Acrobat.Pro.plist". Which further leads me to believe there was an issue with going from free to paid.

I hope this helps someone else out there!

Unfortunately, Acrobat/Reader on Mac OS does not come with the repair option the the Windows version has, and Adobe also does not have the Cleaner tool that they offer for Windows for us Mac users (Download Adobe Reader and Acrobat Cleaner Tool - Adobe Labs ). Here are the things I would do: Reboot your computer. Sometimes that helps to resolve issues that are caused by e.g. resource shortages. If Reader starts up after that, then you are done. If it's still not working, I would remove Reader's preferences. Before you do that, close Reader. On Mac OS, these are stored in a plist file in your Library folder. To see that in Finder, you need to hold down the "Option" key and then go to the "Go" menu. You will then see the "Library" item - select it and then navigate to Library/Preferences/ Here you should find a file named com.adobe.Reader.plist - rename that file to e.g. com.adobe.Reader.plist.BACKUP and then start Reader again. If that makes Reader behave again, then good, if not, you an rename the plist file back to it's original name after you remove the new plist file that Reader just created (again, do that after you shut down Reader).

If you are still not able to use Reader, then it's time to see if it has something to do with your user account. Use a different account on your Mac (you may have to create a new user account first) and try to start Reader. Is it working? Then there is something off in your first account, and it would require much deeper digging to figure out what that is.

Still looking for a response on this... still cannot open PDFs, can anybody help??