You might want to try contacting Liferay Sales in your region. They
can certainly help you with a trial version if the self-service
doesn't work. I'm not aware of multiple download locations, there's
most likely only one.
Alternatively: "it shows some error..." - quite a broad
error description. You could make the root cause more obvious if you
let us know about the exact error message. Or the filename and its
md5, sha1, sha256 or other checksum (and size). Or both.
