The latest version has all the bug fixes and enhancements. Why do you need an older version? Or are you looking for a specific file of that version? The releasenotes has the history of the changes.
The driver for one of my company's products is using an older version of cyusb.sys, because it was released a year or two ago. I was trying to write a utility to debug this product using the .net dll included with SuiteUSB and I am having some problems. I was thinking that trying interfacing an older version of cyusb.sys with the newest .net dll might cause problems. The software normally distributed with this product uses cyapi so i cant pull the dll out of there.
It is also possible something else may be causing my problems.
The version I am looking for is 126.96.36.199
The backward compatibility has been maintained throughout the release. If you are using 188.8.131.52 driver you should be able to work with it even with the latest dll (you should be able to look at the changes mentioned in the release notes to confirm this).
Please update here the issue you're facing here. We should be able to figure out what is going wrong from that.