If Kaltura Capture does not respond you may need to reinstall Kaltura.

Reinstall Kaltura from My Media

1. Open up Canvas.
2. Select Account and then My Media in the drop down menu
3. In your My Media select Add New then Kaltura Capture.
4. A EULA will appear: Check "I agree to the above terms and conditions"
5. Click on Download for Windows below 
6. After downloading, run the downloaded file by clicking on the file name in the lower left hand corner of your browser.  This will re-install Kaltura Capture.
7. Since this is because a crash or lock up, you will have a repair option to select.  Choose Repair.

Kaltura Capture needs to run from My Media after you reinstall.

1. In your My Media select Add New then Kaltura Capture.
2. A EULA will appear again, then again.  Check "I agree to the above terms and conditions"

It should now be fixed.