The answers will be in the details, so please supply the details of your situation.
1. What version of Premiere Elements are you using and on what computer operating system is it running?
2. What is your project's project preset? And what are the properties of this video on the Timeline to which you are trying to add an effect?
3. What is the effect that you are trying to apply to the video? Does the freeze occur when you drag the effect into the video or next when you are editing the applied effect in its the Effects Panel? Is the problem restricted to one particular effect?
Let us start here and then decide what next.
1) I'm using Premiere Elements 12
2 & 3). This is just an ordinary camcorder video file. What i'm doing is blurring certain moving faces in the videos. When editing, I go through the usual steps of creating a title, mosaic effect and then the track matte effect. However, each time when I add the track matte effect, the whole program freezes. I would then have to restart the computer.
Do you think it could be a memory problem with the computer?
Thanks for the reply.
What computer operating system is your Premiere Elements 12 running on? How much installed and available RAM and free hard drive space does it have?
What is the duration of your video with the file size of 159 MB?
a. What are the readings that you see for Editing Mode, Timebase, Frame Size, and Pixel Aspect Ratio (even if they are grayed out) under Edit Menu/Project Settings/General?
b. What is the brand/model/settings for the camera that is recording the video.
I ask the above to get a very rough estimate of your project size and project settings and computer resources.
Are you having any other problems applying effects to your videos even if the Track Matte Effect is not involved? For example, are you having problems with creating text titles in the Titler?
Let me ask you some basic questions..
a. Do you have the latest version of QuickTime installed on your computer?
b. Are you running the program Run As Administrator as well as from a User Account with Administrative Privileges?
c. What video card/graphics card does your computer use and is the card driver up to date according to the web site of the manufacturer of the card? Any chance your computer uses 2 instead of 1 video card/graphics card?
Do you find that your problems are confined to one project or to all projects and one video file or to any video file?
Please review the above and then we can decide what next.