bought a new macbook pro. Acrobat pro 8.1.1 won't open. It has a 20-digit reg. number and Adobe will only process 24-digit. So I'm locked out. What shall I do? Thanks

To be a bit more explicit about this, Acrobat 8.x is over four major releases behind the current release.

The problem is Acrobat 8.x compatibility with the latest version of MacOS, but conversely MacOS' compatibility with existing applications. Apple does knowingly break compatibility with many existing application versions with each new release of MacOS. Applications must use different or very changed system calls and facilities to accomplish the same functionality of older releases of the same applications. Furthermore, the MacOS programming environment is such that you can't have applications that run under both the most recent and very old MacOS versions especially if the applications use very advanced OS functions (such as is done by most Adobe applications). At Adobe, we don't like this problem any more than our customers, but we have no ability to resolve this problem.

If you have a new MacOS system, you need Acrobat DC. (Acrobat 11 will run under the latest OS version, but with restrictions.) Also, be aware that Acrobat DC is available either as a subscription — you pay monthly — or as a so-called “perpetual license” with a single payment. The biggest advantage of the subscription is that you never pay of upgrades; you automatically have access to the latest version is all the latest features, including support for the latest OS version and peripherals. For the “perpetual license” version, all you get are bug and security fixes for a limited period of time and no support for new, incompatible OS releases and new hardware.

          - Dov