Hi Qing,

I suspect this may be a corrupt download. First I recommend trying it from a different network (like on your home internet). If it still happens, let's see if we can get the file size of the IO Module DLL so I can tell whether it was downloaded fully.
Refer here to find the Skyline installation directory: https://skyline.ms/wiki/home/software/Skyline/page.view?name=tip_recover_install
One of the installation directories should have a "Date Modified" from when you tried to upgrade. Go into that directory and find the "Shimadzu.LabSolutions.IO.IoModule.dll" file. Right click on it and go to "Properties".
It should look like the attached picture.