This can happen due to cached lista_updater.xml file.
This should be resolved over time, or you can find and delete cached lista_updater.xml files. If you are comfortable with the command line, you can find them by opening a CMD prompt at your user directory and running the following (where it says YOUR_USER it should instead be whatever your user name is):
C:\Users\YOUR_USER> findstr /s /i /m 2.8.0.0 *.xml
You will get an output that has something like this most likely.
AppData\Local\Microsoft\Windows\INetCache\IE\7IRYH0QI\lista_updater[1].xml
If you delete any lista_updater.xml files like that which appear you should successfully be able to update the software.
If you do not want to run on the CMD prompt, you can browse to C:\Users\YOUR_USER\AppData\Local\Microsoft\Windows\ and look for INetCache folders using your preferred method as well. Or, alternatively, wait for the cache to expire and update at that point.
Thanks for the news about the successful update; the main point of this post is making sure the update would actually be the correct one in the end, so my work here is done!
If you contact customer support they may be able to help you. One common issue I have seen on the forums is that your network is not working or a firewall rule is blocking the install. As a first step you may want to verify your network is working on your machine you are trying to install to and temporarily disable the firewall for the installation process.