I just downloaded v1.18.1 and uploaded the contents of the upload folder through my ftp. When I visit the link to begin the install, this is the error message I see:
Parse error: syntax error, unexpected '?' in /.../include/class.osticket.php on line 186
I'm lost because I haven't touched the files, and I'm running the correct version of PHP, so I don't know why there is an issue.