ArcGIS Pro Offline Help does not get installed if ArcGIS Pro is updated to build 1566.
Last Published: July 22, 2015ArcGIS Pro
Bug ID Number
December 1, 2014
November 24, 2020
After review by the development team, it has been determined that this issue is related to a known limitation with the software that lies outside of Esri's control. The issue's Additional Information section may contain further explanation.
ArcGIS Pro is released in "sets" of setups for each release. The version of Pro and help should match, e.g. both should be 1472, or 1566.
1) Install both ArcGIS Pro and the Offline Help build 1472 at the same time. 2) Update to the new build after installing both.