If you have a Windows 7 64-bit computer and Acrobat Professional just won’t launch at all and will not open ANY pdf file, follow the instructions below. (This happens exactly 30 days after you install the software).
Windows key + E to open Explorer. Navigate to C:\ > Program Files (x86) > Common Files > Adobe > Adobe PCD > Cache > Cache.db
Once you’re there, RENAME Cache.db as “Cache.old.db”
Now you can launch the appliation or open a PDF. It will give you the software license agreement. Accept it.
It will tell you it’s a trial, so you have to click on “License this software”
You must sign in to your Adobe account.
Then enter your license number. And that’s it! All fixed.
Credit goes to Evadobe1 from the Adobe forums for posting this solution that I’ve paraphrased.
Note: if Acrobat opens for a second and then seems to crash and you cannot (again) open any PDFs muchless Acrobat, do this (credit to Amrita Chakrabarti):
For all the users who have faced a problem where Acrobat did not launch after 30 days of serializing with a suite serial number, please execute the following workaround:
1 Make sure you are connected to the internet.
2 Launch a regular CS6 product other than Acrobat or Flash Builder (for example: Photoshop, After Effects, Premier Pro, InDesign, Flash Professional, Illustrator, Dreamweaver.)
3 Click on Help->Deactivate .
4 Deactivate the application. Quit application.
5 Launch a regular CS6 product other than Acrobat or Flash Builder (for example: Photoshop, After Effects, Premier Pro, InDesign, Flash Professional, Illustrator, Dreamweaver.)
6 Accept Eula.
7 Register trial by signing in. Let the app launch.
8 Quit and relaunch the app. Wait for UI to come.
9 Click on License This Software button on the UI.
10 Click on Sign in .
11 Serial number screen will come
12 Enter the serial number in the serial number screen and click Next.
13 Quit app and relaunch the app while connected on the internet.
After this if you launch Acrobat it will launch and run forever without trouble. In case you still face a problem , try relaunching the other CS6 app once more and then launch Acrobat.