We started getting this message mid 2011 after upgrading to Adobe Acrobat Reader 10.
It transpires it has nothing to do with the EULA and only occurs when you try to open acrobat files with the characters ‘CR’ anywhere in the filename.
Now I know that sounds rediculous but it’s true! Test it out if you don’t believe me.
We got around this problem, whilst Adobe took their time with an update, by rolling out a group policy change to a registry entry as outlined in this excellent article, many thanks to Patrick Hoban:
We thought no more of it until recently after we upgraded our terminal server users reported the same error occuring – we had not bothered to factor in the registry change to new builds as we assumed it would be rectified in the near future by Adobe. It transpires they did solve it with version 10.1.1 in September 2011.