Boot Camp Assistant Mac OS X 10.11.6 Cannot create partition

Formatted WDC WD3003FZEX-00Z4SA0 serial number WD-WMC130E4W5E6 as partition map GPT (GUID Partition Table) with file system Journaled HFS+

Terminal shows
/dev/disk0 (internal, physical):
0: GUID_partition_scheme *3.0 TB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Macintosh HD3tb 3.0 TB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3

Opened Boot Camp Assistant to Partition Drive with Fat32 partition.Clicked Continue
The next steps should have been to download software; then, partition drive as Fat32. Instead…

The startup disk cannot be partitioned or restored to a single partition.
The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.