INDYHALLLABS  What sorts of movies are you trying to organize with Multiplex? Our "Automagic" movie detection works with .dvdmedia bundle files, which are really just a renamed VIDEO_TS folder generated by DVD Ripping software. We modeled this after RipIt rips, but any non-compressed video rip can be converted easily. There's instructions here:

http://forum.multiplexapp.com/comments.php?DiscussionID=3&page=1#Item_0

We're not auto-magically finding your compressed movies because there aren't any elegant ways at this point for us to fingerprint them to get metadata for you, so finding those files with spotlight won't give you much of a headstart ahead of dragging the same movies onto Multiplex's main screen and searching for the box art and title info from Amazon, which you can still do for non-DVD videos.

I'm not 100% clear on the issues you're having with manually adding videos. How are you adding them? Are you getting an error? Can you screenshot the error, or provide us with any logs, we'd like to get to the bottom of the problem you're having but they sound unique to any issues we've had reported while we were in beta.

There's not any specific reason why Multiplex would cause VLC to crash, either. The current version of Multiplex doesn't interfere with any existing player defaults, it simply launches the video file in it's default player (in some cases, that will be VLC). Again, any crash logs or screenshots you can provide will help us fix your issues.

We really hope we can clear up your issues with Multiplex!  
(Version 1.0.2)

HEMANTCVTS  Thanks for the reply,

All my movies are video_ts folders ,ripped by mactheripper .

These are not compressed files, If I have to convert these video_ts folders into some other format , this should be included in the basic information provided ,as most of the people have video_ts folders from mactheripper .

I have taken screen shots ,but how to attach them on this forum ?

I am not worried about the money i spent on this application , but without ability to use video_ts folder , this awesome application is a waste.Not many people would be ready to change video_ts to other format , because movie would not played on other platforms.   
(Version 1.0.2)

INDYHALLLABS  You can send us screenshots and any other error reporting to support@multiplexapp.com and we'll be happy to work with you to get issues resolved. We appreciate your feedback, it helps us make the app stronger!

As for VIDEO_TS support, there are some issues with how Spotlight (which we use to find your movies) keeps track of files that makes it a lot harder than you'd think to simply track down VIDEO_TS folders. We can do it, but the obvious way is god-awful slow and we really don't want to kill the user experience.

The whole Multiplex team is attending WWDC next week in San Francisco, and this issue is one of our priorities: we plan to sit down with some of the folks from Apple who can unwravel some inner-workings of Spotlight that should let us track down the VIDEO_TS files you've already created without killing the performance of the app.

Again, we appreciate your feedback, and hope that we can incorporate it into future releases of Multiplex, which is still in VERY active development.  
(Version 1.0.2)