Read this first and make sure you checked all steps: www.csvimproved.com/frequently-asked-questions/635-troubleshooting-import-errors
Don't just say it doesn't work but describe in detail what is happening and add the following information:
* VirtueMart version
* CSVI version (Latest is not a version number)
* Sample of the file being imported
* Collected debug information
Without this information you won't get a useful answer. If no debug log is attached, you will get a request to post it.
Where to get the debug information?
A tutorial (www.csvimproved.com/frequently-asked-questions/390-how-to-collect-debug-information) has been written to help you collect your debug information. For CSVI 3, there is a video available (www.csvimproved.com/downloads/file/18-collect-debug-information)