Adobe Acrobat XI Pro version 11.0.23 , released on November 14, 2017, was the final update for the Acrobat XI product line. It is primarily a security and maintenance patch designed to address critical vulnerabilities and stabilize the application. Essential Status and Security Information End of Support:
Resolved an issue where parts of images or text disappeared when using the Reading Order tool for figure/caption tagging. Download Adobe Acrobat Xi Pro 11.0.23 Fixed
This update is often cited by the community as a "fix" for persistent crashing issues seen in earlier XI versions. How to Download and Install Adobe Acrobat XI Pro version 11
Although support had ended, this final "planned update" was released shortly after to provide critical security mitigations (APSB17-36) and bug fixes. Usage Risk: Adobe Acrobat XI Pro version 11.0.23