Knowing this will help me provide the exact solution you need. ACROBAT XI PRO SHUTTING DOWN - Adobe Community
To reinstall, users have had to contact Adobe directly for a valid download link, as public downloads were removed. adobe-acrobat-xi-pro
Which (Windows/Mac) are you currently using? Knowing this will help me provide the exact
Due to the security risks, the best course of action is to move to a supported version (Acrobat DC) or use alternatives like Foxit or PDF Xchange. adobe-acrobat-xi-pro