I initially set up the project and uploaded photos from a different drive than that of the project file. I received this error and then copied the images from the other drive to the same drive as the project file. When re-opening the project file I am not prompted to select where the images are and still not able to upload to the cloud.
[Error]: Error e0502d: Cannot upload project SLO040_06142018.p4d.Some images are in different drives
Close pix4dmapper. Delete the files from their orginal folder. Start the pix4dmapper and now it can’t locate the images so you can choose the folder on same drive. Upload the project and you are done