FCPX 10.2.2 won't save REDCODE RAW settings to .RMD

I keep getting this error when I try to modify REDCODE RAW settings on .r3d clips from a RED ONE camera - " Final Cut pro is unable to save the REDCODE RAW settings. Make sure the REDCIDE RAW settings metadate file (.RMD) is not in use by another application."

I've updated to the latest Red Apple workflow plugin (v6 - also tried v7 beta).

I've made sure the disk/folder/file permissions on the .R3d are all set to read/write.

I've tried making a .RMD by opening the files in RedCineX first, the re-importing into FCPX, but I get the same error.

My system specs are:

OS X 10.10.5

MacPro3,1

Quad-Core Intel Xeon

2.8 GHz

Number of Processors: 2

otal Number of Cores: 8

L2 Cache (per Processor): 12 MB

Memory: 20 GB

NVIDIA GeForce GTX 285

Any ideas on how to solve this would be appreciated.