Hi,
I had the same problem or better the same windows error message.
I was trying t install the upgrade inside AS4.12.6 un upgrade, but in the B&R Sites the was the documentation to install outside the AS. Both for the 4.12.7 or for the 4.12.8.
So the solution is to follow the B&R documentation.
Installation_of_Automation_Studio_Version_4.12.7_English.pdf
Installation_of_Automation_Studio_Version_4.12.8_English.pdf
“
1 Automation Studio 4.12.8
1.1 installation
Run the executable file Automation Studio.exe from the installation directory above the
already installed Automation Studio 4.12.6.
Please use the B&R Automation Studio upgrade dialog if AS 4.12.7 is already installed
“
I usually install using the upgrade tool inside AS , I don’t often look at the download section of the site of B&R; but there is a link to show this different procudere.