How much free space does your disk actually have? (Bottles don't have their own notion of space on their virtual C: drives. The C: drives are just a directory on your hard disk and Windows programs running under CrossOver are free to use as much of that disk as any other program.)
CrossOver usually reports the space correctly, although bugs are possible. Some Windows programs, though, aren't prepared to cope with really huge disk sizes.
Lastly, it's also possible that the program is getting some other error entirely, which is wasn't written to expect, and it's misinterpreting that error as a lack of disk space.