If you are uploading a CSV file via the CSV Upload Tab and you get the following feedback in theĀ Previous Uploads section, please note that this does not necessarily mean that the whole file is invalid (eg if you have provided a file of 300 records).

The feed system will stop if it finds 10 invalids in a row, this can be the first 10, or even 10 midway through a file.

A key give away will be Row Count, which suggests the amount of records the file has looked at.

A common reason you might want to consider:

Does the CSV File contents match the order in the Selected Fields?

The summary report shown in the screenshot above has a downloadable file that you can retrieve "report" which will give you per lead advice when it comes to invalid leads.

This may help you come to a conclusion on whether it's a common and easily amended issue or if each lead needs to be looked at on a case by case basis.