That is odd… you mention it was created and exported from MS Project. That is important. There are many programs that export as .mpx or .mpp and it is not formatted correctly. In this case do you have custom fields or anything “special” in your exported project? We are making some changes in the upcomng version. If you want to send us the file info@projectlibre.com we can take a look on the Cloud version if it is imported correctly.
