Video convert error while convert .VOB to .3gp

I am using Total Video Converter and I boot registry code. It's working good but while I'm try to convert a .VOB movie file to .3gp on its default setting and click to start convert every time it's give me a error message called "Error while opening codec for output stream – #0.0". How can I solve this type of problem and how to convert .VOB to .3gp file?
Error while opening codec for output stream #0.0 – maybe incorrect parameters such as bit_rate, rate, width or height
OK
