There are a few errors that are common within CSV imports in dlvr.it.
1) Invalid CSV: This error indicates that your document is not saved in the correct format or that you don't have the correct headings implemented. Check out our sample CSV file to make sure that your document is formatted correctly. Also, this could mean that there are spaces in your headers where they shouldn't be. Make sure that your headers have the correct spacing.
2) Invalid Characters: Our system may tell you that there is a character in a specific line that isn't compatible with our character set. Our system uses the UTF-8 Character Set. This may require that you look for non-standard characters within your document. You can use a UTF-8 validator to make sure that your characters are allowed in our system.
3) Duplicate items: Our system may detect duplicate items already within your Queues. These items will not be permitted in Twitter because Twitter doesn't allow us to post the same content to more than one Twitter handle. This can only be accomplished by Retweeting.