I receive the error message shown below, when attempting to install Maintenance Pack updates to v15.8.
"The installation source for this product is not available. Verify that the source exists and that you can access it."
Release : 15.8 MP3
There appears to be an issue when trying to run a Windows MSI application and the system needs to be rebooted.
Rebooting the system released what might have been a MSI hung process.
Error code 1619.