Adobe Acrobat X Pro version 10.1.16 was the final planned update for the Acrobat X family, released on October 13, 2015. Because Adobe ended support for Acrobat X on November 15, 2015, this software is considered "End of Life" (EOL) and is no longer officially distributed or updated by Adobe. How to Download the 10.1.16 Update
A major caveat: You cannot find this file on Adobe.com anymore. Adobe purged legacy patches around 2019 to push users to the cloud. The official filename for this patch is: Adobe Acrobat X Pro Update 10.1.16 Download
Acrobat X Pro is end-of-life. This update will not add features nor improve compatibility with modern operating systems beyond the original product limits. For new OS or PDF feature support, upgrade to a current version of Adobe Acrobat Pro (subscription). Adobe Acrobat X Pro version 10
AcrobatUpd1016.msp (for Windows) or AcrobatProUpd1016.dmg (for Mac OS X 10.10 or earlier)ftp://ftp.adobe.com/pub/adobe/acrobat/win/10.x/ftp://ftp.adobe.com/pub/adobe/acrobat/mac/10.x/Acrobat_X_Pro_10.1.16_Setup.exe (the real update is an .msp or .dmg, not a full installer).