Hi Wei Liu,
I had a similar problem to yours when I wasn’t able to run one of the Optiwave products (I think it was OptiBPM) after downloading it from the website. The download itself didn’t show me any errors. However, I have got errors when I was running it and trying to open links with examples… In my case, the problem was fixed very easily: as it was mentioned above by Damian, I downloaded the trial version of the software again, and it worked.