Can't pack file error

[Matt]

I am getting an error i have not seen before. 
While building a 6000 50 MP image orthomosaic I am getting a Cant Pack file error (see attached image).
I gave 500 gig spare on the System Disk and 1TB spare on the data drive and @ 380 gig of RAM. 
Any help would be appreciated

----> Well it seems it was because i was using .cr2 files to build the Ortho.  They have been supported in the last few builds for point detection/alignment but when writing the orthos the images are not optimized and are too large for my 2 TB M2 disk.