Adobe Acrobat automatic updates :(

If I were you I'd just sit back and let it download and install the updates, because then it won't install any more updates, being that it will be up-to-date.

If you don't let it install updates - you'll be back here in a while complaining because Acrobat can't read something or other that you urgently need to read.

The reason for it's inability to read the latest PDF documents will be because you stopped it from updating. ;)

Open Adobe and click Edit, Preferences. You should see General in the left pane. Click on it.
Under Application Startup, uncheck Check for updates.
Click Trust Manager.
Under Automatic Updates, uncheck both boxes.