The final updates for the 2015 “Classic” track were around version (mid-2016). Later updates (15.0xx) require a newer base installer.
Once you have downloaded the correct .msp (Microsoft Patch) file, follow these steps: adobe acrobat pro dc 2015 update download
Adobe Acrobat Pro DC 2015 reached its end-of-life on July 7, 2020, meaning it no longer receives security updates or technical support. Users can still apply the final update, version 15.006.30527 from August 2020, via the Adobe FTP site, though upgrading is recommended due to security risks and lack of support for modern operating systems. For more details, visit Adobe's Release Notes Adobe Acrobat 2015 and Adobe Reader 2015 End of Support The final updates for the 2015 “Classic” track
Before you proceed, check your exact version: Users can still apply the final update, version 15
Because Adobe has moved to a subscription model (Creative Cloud) and Acrobat Pro DC 2015 is considered "End of Life" (EOL), finding updates requires looking in specific archive locations rather than using the standard "Check for Updates" button, which often fails for this version now.