LR update failed with error code 7.
Install MSI payload failed with error: 2 - The system cannot find the file specified.
MSI Error message:
ERROR: Third party payload installer Adobe_Lightroom.msi failed with exit code: 2
Second time now - solution please.
Code 6 & Code 7 http://helpx.adobe.com/creative-suite/kb/errors-exit-code-6-exit.html
or
A chat session where an agent may remotely look inside your computer may help
Creative Cloud chat support (all Creative Cloud customer service issues)