Have you updated Premiere Elements 13 Editor and Elements Organizer 13 to 13.1 update yet? If not, please do that from an opened project's Help Menu/Updates.
What is the audio format of those .mts files - Dolby Digital Stereo or 5.1 channel or something else?
Do you have any problems with the problem file if you import it into the Premiere Elements 13/13.1 Editor?
Please consider and supply more information including more information about the problem file properties and duration.
(Brand/model/settings for the camera that recorded the .mts should give us this part of the information that is needed in the troubleshooting.)
I have updated to 13.1. What I can see is the audio format is 5.1ch Surround. If I import the clip to editor from the organizer or from a file on my hard drive the audio seems to play to the end of the clip. It seems it will not play the sound to the end of the clip in the premiere elements organizer only. The camera I have is a Sony HD AVCHD. Does this information help. I would like to be able to play the clip in organizer before importing to the editor to get some idea of what I want to remove from the clip file.
Thanks for the reply with important troubleshooting information.
Video imports into the Elements Organizer can have varying problems from Elements Organizer version to another. The issues faced often cannot be explained away by "missing decoders" or "codecs" since a file that has a problem in one version of Elements Organizer may not have the problem with another version of Elements Organizer on the same computer.
What computer players do you have on your computer besides the required QuickTime 7? Please confirm that you have QuickTime 7.7.8 installed on your computer along with Elements Organizer 13/13.1. On your computer, do you have any burn software that came a Blu-ray burner, such as Cyberlink software?
For troubleshooting purposes now only, you could try the following which has worked on several occasions. Instead of importing the video into the Elements Organizer directly. Please do this. Import the video into Premiere Elements project with Premiere Elements' Add Media/Files and Folders. When you do that, you get a copy of the file in Premiere Elements Editor but also one automatically placed in the Elements Organizer 13/13.1. Does the file placed in the Elements Organizer this way have the same problem as before? What is the duration of the video clips involved?
Please consider if you want to send a sample of the clip as a shareable link in your thread. I recently did that for another only to find out I did not have the problem while the user did. Did you read that thread Sound Problems with Premier Elements 13.1 Organizer
I need to get back to that user.
Please consider and then we will decide what next. If you give the model/settings for the Sony that recorded the video in question I will try to find a sample to download from an online review of the camera - if you do not want to send the file as a shareable link from Google Drive or Dropbox with permissions in order.