Solution: Missing msvcr100.dll - reinstall Reader DC, and even Acrobat XI will start working again.

I'm using Windows 10 and am still using Acrobat Professional XI. Updated to Windows 10 Version 1607, and Acrobat failed to launch. Error messages said that mcvcr100.dll and msvcp100.dll were missing.

I tried downloading and reinstalling the latest version of the Microsoft Visual C++ Redistributable Package, but it was of no help.

I then decided to see whether Adobe Reader DC would work, which had been loaded and used before the Windows 10 update. Rather than immediately starting when I launched it, it reinstalled itself and then finally opened. After that, and without rebooting, Acrobat Professional XI started working properly.