problem with serial number

[Derek40]

I have Acrobat 9 Pro running under Win 8.1. It has been running without any problem for years, now it wants my serial number, which it rejects and I can't use the program. Any ideas?

Thanks

[Sara_Forsberg]

Hi derek40,

Acrobat 9 wasn't tested with Windows 8, so it's not officially supported on that operating system. However, I'm wondering what's changed on your system before Acrobat started prompting you for a serial number. I'm also curious about the error that you're receiving--can you please provide the exact error message?

Best,

Sara