Hi sartajbedi, and welcome to the Tiki Community (your 10th post!)
jcapture uses Java, and that is probably the source of the issue. Can you upgrade your java to the latest stable version?
And then, you can manually enable the java console so that it shows up whenever you attempt to run any java applet (such as jcapture). This way you will be able to see whatever warning or messages the java console outputs in your system, and find out the source of the issue to get it solved.