I haven't played UO in 3 years or so, so I decided to download my copy of samuria empire, uoassist and everything like I had before and start playing again... but I have no option to play 3d... what's up ???
UO Third Dawn (3D) was discontinued a few years ago. It was replaced by the Kingdom Reborn (KR) client. That client was discontinued earlier this year and replaced with the Enhanced Client (EC). At this time we may choose to use the Classic Client (CC) or the Enhanced Client (EC). The EC is considered by some to be the best alternate client made available and from a functionality standpoint I can agree, but many have grown tired of all the attempts to replace the CC tat they have given up on it and will only use the CC. The EC is still considered to be in beta and has its on set of die-hard fans.
Myself, I find I use the Classic Client because I like the art better. It is like comfort food for me as I have been used to it since 1997, but I don't mind the EC and if it was the only client available I would use it with out too much groaning.
Since it has been a few years for you I would suggest giving the EC a shot. It has a number of the features that we used to get from UOAssist and UOAutoMap built right in. There is also a new mapping program called "UOCartographer" available that works with either client and is a real work of genius:
http://vboards.stratics.com/showthread.php?t=168538
Good luck and welcome back!