I've searched through the web and this seems to be a recurrent problem that affects various versions of Acrobat. I've reinstalled Adobe Web Premium after a clean re-installation of Mac OS X 10.6.8.
Acrobat 8 used to work fine, but now it closes after a few seconds - no crash, just closes. I tried to clear the preferences folder and I had to introduce the serial number again. When I re-entered it, it says it's not a valid number, although the number works fine on Photoshop.
How can I solve this?
Thank you