Can't restore missing LUTS FCP 10.8.1 on new iMac

Hi there. I worked on a project on my old iMac, and used a Custom BlackMagic LUT on several clips. I keep the project on an external SSD, and when I first opened it in my new iMac, I had no issue. Now if I open it, I get the red 'Missing Camera LUT' icon on those clips. I've redownloaded the LUTS and put them into the new iMac's appropriate folder for Custom LUTs, then restarted. Still just a logo, and the Info for the clip does not show the application of a Custom LUT. I've also tried applying it afresh, and no luck..

Any help would be really appreciated!