When I press the play button, it freezes, then always greys out and stops responding! Someone please help!

Well that's rather little information for us to help you.

Which kind of clip do you want to play? (run ffprobe <clip> and post the output here.)
Do other clips play?
Which version of kdenlive?
What is the output if you run kdenlive from command line and play the clip that stalls kdenlive?

Well, it happens even when there are no clips.
Version 0.9.6
It still doesn't work when I run it from terminal. It does say

Code: Select all

ERROR: Could not load classifier cascade /usr/share/opencv/haarcascades/haarcascade_frontalface_alt2.xml
QWidget::insertAction: Attempt to insert null action
QWidget::insertAction: Attempt to insert null action

I dont know if that has anything to do with this though.

Version 0.9.6 is probably too old to get effective support. Try to upgrade.

kdenlive 0.9.6. is rather old, the current version is 15.08 (since 0.9.6. there were 0.9.8, 0.9.10 and 15.04).

In your profile you say, ubuntu is your distro. You may want to check the sunab ppa version (mentioned here: viewtopic.php?f=269&t=126292#p337882) Using kdenlive from other ubuntu repos it seems to be tricky to get melt and kdenlive to the correct versions.

Ok, ill try that.

I uninstalled 0.9.6 and downloaded 0.9.10, but it still happens. This happened ever since my computer's battery ran out while I was editing a video yesterday.

Maybe your setup file is corrupt. It might help if you rerun the configuration of kdenlive.

Either run the configuration assistant (settings menu) or delete the kdenlive configuration file which is stored at
~/.kde4/share/config/kdenliverc (until 0.9.10)
or
~/.config/kdenliverc (since 15.04)

Hmmm, the error messages about not finding some openCV Haar cascade stuff are strange, if you just want to play a video?

That kind of stuff is used only (AFAIK) in the face detection (face blurring?) effect.

Since you mentioned running on a depleted battery ... did you check the filesystem? Afterwards, make sure that there isn't some lost+found stuff that turned up during the file system check and that might indicate some broken system stuff...