Upload error in CCTM media custom field

This is an issue that comes up repeatedly because WP’s integration of this bit of functionality is so myopic it hurts. The CCTM attempts to workaround this, but I can’t give you any useful information without knowing exactly how your fields are defined and exactly how you tried to upload the image (there are several options of each). See https://code.google.com/p/wordpress-custom-content-type-manager/wiki/ReportingBugs

I would recommend downloading and using the the development version of the plugin — I’ve done some work on this functionality recently so there’s a good chance the issue is resolved in the development code.