Would really appreciate some help to upgrade Lightroom here. I am using the standalone Lightroom 6.0, and wanted to update to the latest 6.8. I'm using a Mac with Sierra. I have checked several times for updates via the Help/Updates menu, and after checking the message states that I am up to date.
Because the check for updates method is clearly not working I've tried to solve this by downloading the actual 6.8 update download instead, but when it comes to installing the download I'm shown 2 folders: AdobePatchInstaller and Payloads. I open the AdobePatchInstaller, given permission to install, progress bar quickly goes from 2% to complete and then to: Update is not available. Error U44M2P28. Do I need to uninstall 6.0, and if so how do I do this? I have since moved Lightroom to trash and then tried to install the upgrade, but with the same error message produced. Thanks for help with this.
Thank you dj - problem solved. The solution seems to have been to simply download 6.0 again from scratch, rather than any of the incremental updates I had tried earlier. Once 6.0 was successfully reinstalled, the Help/Check Updates route worked perfectly normally and 6.8 displayed for download. My only real difficulty was the first step of how to uninstall my original version and I resorted to using the third party AppZapper as used in the link you provided. There must be a way of using Apple's own system for uninstalling software in a quick and easy way but after searching I was unable to find one. Anyway, I'm grateful to be running the latest Lightroom. Thanks again.