I tried the above suggestion of uninstalling the (KB3035583) update and restarted, but it did not fix the problem for me; the SSD optimizer still crashes every time @ 90% .
I have the exact same problem with Intel 535 240GB SSD (intel SSD Toolbox v 3.3.0 crashes at 90% every time when optimizing) I have a Intel 535 SSD, an Emachine Laptop e725, and am running Windows 7 Home Premium 64 bit. FYI, I am running in IDE ...