Not sure if this is common knowledge, but if you need a previous version of the SDK that is not listed on the Developer site, you can modify the URL of an MSI listed with the version you need to target and paste that into the window to start the download. As an example, IceLib SDK 2017R3 is the oldest version of the SDK visible at developer.inin.com. If you right click the MSI for your platform and copy the URL, change the version (2017_r3) to an older version (2016_r4) in the URL and you will get the 2016_r4.msi. Here is an example URL "http://help.inin.com/developer/cic/installs/icelib/icelibsdk_32bit_2016_r4.msi"