Q: Cant use free space. Couldn't read partition map (-69876)

Hi all,

just bought a new iMac 27" with 512 SSD. After bootcamp failed to install i did a reboot. Unfortunately bootcamp would not want to reinstall. Checking Disk Utility showed free space in the partition table. I can not delete it ( error code Couldn't read partition map (-69876)) so i'm kinda stuck now with 1 gb off free space that not allows me to use it and prevents bootcamp from installing Message:

The startup disk must be formatted as a single Mac OS Extended (Journaled) volume or already partitioned by Boot Camp Assistant for installing Windows.

Around 100gb available for bootcamp but this cannot be merged to 1 disk as required...

diskutil list:

/dev/disk0 (internal, physical):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:      GUID_partition_scheme                        *500.3 GB   disk0

   1:                        EFI EFI                     209.7 MB   disk0s1

   2:          Apple_CoreStorage Macintosh HD            399.4 GB   disk0s2

   3:                 Apple_Boot Recovery HD             650.0 MB   disk0s3

   4:                  Apple_HFS NewName                 99.4 GB    disk0s4

/dev/disk1 (internal, virtual):

   #:                       TYPE NAME                    SIZE       IDENTIFIER

   0:                  Apple_HFS Macintosh HD           +399.0 GB   disk1

                                 Logical Volume on disk0s2

                                 3DB995B0-D676-471E-839C-571916143CA0

                                 Unencrypted

Please advise what to do.

Many thanks.

Lennart