Just tried it; getting the same error.

EDIT:
I should add that, in the Device Explorer, the clip I am trying to import does not have the yellow indicator that means it has not been imported yet, but I don't see it anywhere.

Can you see the clip in your Device Explorer > Device Properties > Capture Folder?

Yes. The clip is in the folder. I am still given the same error when importing from that location.

Post the full file properties you get with MediaInfo.

What is this supposed to do? According to reviews, this program contains malware.

You may not have the codec needed to open the files in SMS installed on your machine.
MediaInfo gives "useful information about your media files that others here will find useful in assisting you to solve your issue.".
As for malware etc., see this thread New MediaInfo Download Issues.
I myself use an older version (0.7.60) without issues.

Ok, I downloaded that version. Now, which file do I need to examine, and how should I present the properties (i.e. screen capture, text, ect.)?

The file you are trying to use is relevant.
See an example of a post e.g. here.
MediaInfo View > Tree.

General
ID : 0 (0x0)
Complete name : D:\Videos D\Garbros\Smash VS\00481.MTS
Format : BDAV
Format/Info : Blu-ray Video
File size : 1.91 GiB
Duration : 11mn 33s
Overall bit rate mode : Variable
Overall bit rate : 23.6 Mbps
Maximum Overall bit rate : 24.0 Mbps

Video
ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4.0
Format settings, CABAC : Yes
Format settings, ReFrames : 2 frames
Format settings, GOP : M=3, N=15
Codec ID : 27
Duration : 11mn 33s
Bit rate mode : Variable
Bit rate : 22.4 Mbps
Maximum bit rate : 22.7 Mbps
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate : 29.970 fps
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Interlaced
Scan order : Top Field First
Bits/(Pixel*Frame) : 0.360
Stream size : 1.81 GiB (95%)

Audio
ID : 4352 (0x1100)
Menu ID : 1 (0x1)
Format : AC-3
Format/Info : Audio Coding 3
Mode extension : CM (complete main)
Format settings, Endianness : Big
Codec ID : 129
Duration : 11mn 33s
Bit rate mode : Constant
Bit rate : 256 Kbps
Channel(s) : 2 channels
Channel positions : Front: L R
Sampling rate : 48.0 KHz
Bit depth : 16 bits
Compression mode : Lossy
Delay relative to video : -67ms
Stream size : 21.2 MiB (1%)

I am not able to tell you what the problem is, if you have double-checked your import process for any oversights and the computer meets the system requirements listed here.
I seem to be able to import files with similar properties from the Device Explorer, from the Capture Folder (Imported Media) and from MSP Explorer. Also copied the file from (SD card) Private/Avchd/Bdmv/stream to the computer and dragged it to the MSP 13 project.
Hope someone has a solution.

Can you use the software that came with your camera (and what is the camera)?

Hi Garbotron,

Based on my experience of having to remove, clean system and then re-install Movie Studio 12 and 13 to get them working, you might want to consider that.

In my case, my Mother Board died and I installed a new MB and CPU. Windows and all my other programs worked except Sony products. Several of these I was simply able to re-register, but Movie Studio refused to even load, so I used an uninstaller/cleaner program (Revo) to clean my system, then re-installed and re-registered. Still, several features in Movie Studio 12 would not function, so I went through the entire sequence once more, and on the second re-install both MS 12 and 13 Platinum are now working.

By the way, I also had to re-install Quicktime to get Movie Studio to "see" it.

So, this might not solve your problem, but it seems evident that one or more of your codecs are not installed properly. If it were me, that would be my next step.

It could have been some other program you installed, or a Microsoft update that has caused your problem. Who knows at this point. You just want to get your system running again.

One other quick idea. Are you sure you purchased the Platinum version and not the plain vanilla Movie Studio?

AVCHD files don't need to be imported via the Device Explorer. Can you copy the file using Windows Explorer to a new folder, then create a new project add add it directly to your timeline?

I'm trying to see if it is a program issue or a project-related issue.

Also, what happens OUTSIDE of Movie Studio when you double click the .mts file? What program does it load to and does it work OK?

Other related questions...
- Are you sure it is a serial number for Movie Studio Platinum (Check My Account>My Software).
- Do you have DVD 5 installed? I know the AC3 for 5.1 encoding (yours is 2.0) is installed via DVD Architect, but I had thought that Vegas could still import the file without DVDA. Kind of a shot in the dark.

Sorry for the late reply. Been busy.

I cleaned my C and D drives using Control Panel tools. I then uninstalled Movie Studio and reinstalled from the disc. The files are now able to be imported just fine.

When I had the trial I changed the name of a codec to fix a problem where mp4 files wouldn't play. Could that have caused this?

Can't say. Maybe?

I agree with Markk655 here:) Just for the record, did you change the name of the codec or the codec itself or maybe the file extension?

I changed the name, adding an extra letter or something like that. Several people said it was a solution for playing mp4 files.

WELP, mp4s aren't working again. They just display green.

Edit:
This is what I had renamed before:
compoundplug.dll

Just a thought. Would you find anything relating to your problems in the thread below?
http://www.sonycreativesoftware.com/forums/ShowMessage.asp?ForumID=12&MessageID=900211