Send to Final Cut Pro in Color off an external Hard Drive, causes Color to Crash

Okay, so I'm having some Color issues guys...

I'm color correcting a feature right now, and just completed the CC with Color. I did the entire color correct on an internal hard drive on a Mac Pro. My client wanted to take a look at the CC on a different machine, so I transferred all of the FCP files, Color Projects, footage, etc. (the ENTIRE directory from my machine) onto an external hard drive....

...When I opened the color project from the external drive on his machine, all of my media was gone, so of course I reconnected the media (directly from the source, the same source files I edited with in FCP), and everything was fine. My grades were there, and everything looked great....

....I rendered my Color sequence and tried to Send To Final Cut Pro, and color crashed on me. It continued to do this....

....I went back to my machine and tried to Send To Final Cut Pro, and everything worked just fine. What went wrong with the data transfer? Is that the reason Color keeps crashing? Is it because I relinked the footage in Color to the original source files? It doesn't make sense to me. All of the data from the original drive was moved to an external and relinked.

I'm pretty new to Color so any help would be appreciated. Thanks so much!

-Chris