Does your csv contain only 1 point? If so this is a known issue - the upload fails and the error message is bogus. In this situation a simple workaround is to have more than 1 point and you can then delete the 2nd point after the import completes. If your csv contains multiple points please post it here, if possible, so that we can investigate the problem.
You mention that your nmf contains - points, lines and areas - currently the CSV importer in Explorer Online only supports points. This upload facility has just been released recently but I'd expect it's capabilities to improve & grow in subsequent releases. I'll pass on your request for better interoperability between Explorer Desktop and Explorer Online but feel free to post this as a suggestion on the ideas site under the Explorer Desktop category.
Hi, Rather irritatingly the error message that you are seeing is completely bogus. I think the reason for the import failure is simply that your lat/long coordinates needs to be in geographic coordinates i.e. decimal degrees. Mike