Windows 10 build 17763 (rs5 release)

Windows 10 build 17763 (rs5_release) is the official RTM build of Windows 10 October 2018 Update.

Data loss
The original release of this update from 2 October 2018 has a bug that deletes every file in the Documents, Music, Pictures, and Videos directories of users' profiles when upgrading from older versions of Windows. Back up all data before updating or disable the "Delete user profiles older than a specified number of days on system restart" group policy prior to installation if the updating SKU is Pro.

This update revision was pulled from Windows Update on 6 October 2018. The data loss bug was later fixed, and a later bugfixed version was released to Insiders on 9 October 2018. It was re-released on Windows Update on 13 November 2018.

Activation bug
The re-release of the update included another bug in which Windows 10 Pro licenses would show as not being activated. If a user used the Windows Activation troubleshooter to fix it, it would say that the device had found a digital license for Windows 10 Home and that they had to install it to activate the device. It was made available for advanced users on 18 December 2018.