Problem : An installation of Acrobat Reader may override an existing installation of Acrobat Std/Pro.
Resolution : Run Acrobat Std/Pro on its own in order to re-register components necessary for communication with Probate Plus. Or, uninstall Acrobat Reader, leaving just your copy of Acrobat Standard/Professional intact.
It may also be necessary to carry out a repair of Acrobat Standard / Professional by using Windows add/remove programs then select to "change" Acrobat and run a repair installation. This will set Acrobat's Windows registry keys and Acrobat COM objects to their correct status so that Probate Plus is able to detect it.