Hi lqu17 and welcome to LQ.
Please note that you have three new threads open with questions. People have asked for feedback in the other two, and this also applies here.
Please provide some better information as to what led to this point. What Linux distribution and version you have, what you intend to accomplish and whether or not you are following a reference guide to lead you down the path where you've put in this one command that did not work. Some history here will be very helpful for other users to give you advice.
A LQ link to consider reviewing is the
Site FAQ which will give you further information on things like how best to formulate a good question where you understand the most helpful information to share to increase the chances of persons being able to aid you. Also there are some links there to show you how to use the LQ interface if there are any questions.
For now, it is best to update your question with the history of what led you to this point as well as the Linux distribution and version you are using.
And it is not that people don't understand what dradis is, however we need to know your expertise, whether or not you are using a guide, and as already said, the Linux distribution. Some new users, or even experienced ones, may try very mismatched things and therefore a simple one-phrase answer may not be best, they may need additional clarifications.
