Last time it didn't work for me, this is what I had to do:

1. The update comes from: http://www.aatrix.com/sage300construction so if the automatic update does not work, get the download just mentioned, and
   1. Save the download locally. Right click on the sto.exe that you saved and choose “Run as administrator” and run the install. 

There's also a Knowledgebase Article about this:  https://us-kb.sage.com/portal/app/portlets/results/viewsolution.jsp?solutionid=222924950026807&page=1&position=5&q=aatrix%20update%20error 

Last time it didn't work for me, this is what I had to do:

1. The update comes from: http://www.aatrix.com/sage300construction so if the automatic update does not work, get the download just mentioned, and
   1. Save the download locally. Right click on the sto.exe that you saved and choose “Run as administrator” and run the install. 

There's also a Knowledgebase Article about this:  https://us-kb.sage.com/portal/app/portlets/results/viewsolution.jsp?solutionid=222924950026807&page=1&position=5&q=aatrix%20update%20error