I have tried to update in my mac Lightroom 2015 from version 6.0 to version 6.3, but it is not possible. "Código de error: U44M2P28"
Please uninstall Lightroom using the Adobe Cleaner Tool : Use the Adobe Creative Cloud Cleaner Tool to solve installation problems
And then download and install the updates of Lightroom 6 from the following link : Keeping Lightroom Up-to-Date
Ok. Now all is working well. Thank you very much.
You are Welcome, Glad to help.