I'm getting an error message when trying to sync the BB to the SD card.

I have tried several times to get songs from the BB Manager to the BB Pedal. I’ve watched the videos and am pretty sure I followed the process, but to no avail?!?!?
The error message reads: Invalid Song – There is at least one invalid song in the project! Make sure all song parts contain a Main Drum Loop.
I am at a stand still! Jim

Take your pick - this is one of the most common issues that is reported. I have never had this issue, but it sounds like you were experimenting and created a new song but did not add anything to it - so it has no loop attached. Unfortunately the error message is not very helpful so you can either start from scratch or find it - it will be “highlighted” in red. Ideally it should tell you which song. Below are the topics discussing this issue:

You accidentally a main part of the song. That’s why you can no longer synchronize the project.

You need to go through all the directories, find that song and fix it.
It should look like that:

You will be able to synchronize the project as long as no such directories remain in your project.

Taken from here - http://mybeatbuddy.com/forum/index.php?threads/project-not-synching.2082/#post-9306.