Must be installed over Acrobat XI (11.0) or a later incremental version. Key Fixes & Improvements
If the automatic updater is no longer active, you can download the .msp patch file directly from the official Adobe FTP or support archives. FULL Adobe Acrobat XI Pro 11.0.23 Patch
Adobe officially ended support (EOL) for Acrobat XI in October 2017. This means that while the 11.0.23 patch exists, there are no newer updates after this version, and the software is considered legacy. Steps for Manual Installation (Windows): Must be installed over Acrobat XI (11