After a month of activating Adobe Acrobat it is not working again

Can anyone assist me on this issue.

We have purchased Adobe CS6 and we have installed the complete software and activated the license to one computer and is working fine.

However, upon installing the Adobe Acrobat only to another computer and activating the license. For at least two months then issue will re-occur.

Is license for Adobe CS6 valid only for one user or two?

Awaiting response.