When you specify a target version of Acrobat and Adobe Reader, you must ensure that you have the correct version of Acrobat installed that matches the target version saved; otherwise, you may get an error or warning message when you click the Preview PDF tab. For example, if you select Acrobat and Adobe Reader 6.0.2 or later as the target version for the form, ensure that you have either Acrobat or Adobe Reader 6.0.2 installed. Similarly, if you select Acrobat and Adobe Reader 7.0.5 or later, ensure that you have Acrobat and Adobe Reader 7.0.5 installed.