It seems unlikely that a 3ga to jpg conversion is possible, given that .3ga files are typically audio files and .jpg are image. But sometimes audio files contain little thumbnail previews (album covers etc.) that can be perhaps export with a proper tool and saved as pictures.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
If you find entry that you feel is flagged as bad wrongly, please tell us in the discussion below with as much as information as possible so we can fix it.