"APFS Container Resize error code is 49153" when adding MS-DOS (FAT) partition I am trying to create a 20GB MS-DOS(FAT) partition on my Macintosh HD drive.
Upon defining the partition in Disk Utility and running the process, it throws up this error...

Running operation 1 of 2: Add “parrot” by splitting “Macintosh HD”…
Resizing APFS Container designated by APFS Container Reference disk1
Verifying storage system
Using live mode.
Performing fsck_apfs -n -x -l /dev/disk0s2
Checking volume.
Checking the container superblock.
Checking the EFI jumpstart record.
Checking the space manager.
Checking the object map.
Checking the APFS volume superblock.
Checking the object map.
Checking the fsroot tree.
Checking the snapshot metadata tree.
Checking the extent ref tree.
Checking the snapshots.
Checking snapshot 1 of 1.
Checking the APFS volume superblock.
Checking the object map.
Checking the fsroot tree.
Checking the snapshot metadata tree.
Checking the extent ref tree.
Checking the snapshots.
Checking the APFS volume superblock.
Checking the object map.
Checking the fsroot tree.
Checking the snapshot metadata tree.
Checking the extent ref tree.
Checking the snapshots.
Checking the APFS volume superblock.
Checking the object map.
Checking the fsroot tree.
Checking the snapshot metadata tree.
Checking the extent ref tree.
Checking the snapshots.
Verifying allocated space.
The volume /dev/disk0s2 appears to be OK.
Storage system check exit code is 0.
Shrinking APFS Physical Store disk0s2 from 250,790,436,864 to
230,790,434,816 bytes
Shrinking APFS data structures
APFS Container Resize error code is 49153
A problem occurred while resizing APFS Container structures.
Operation failed…


I have added Macintosh HD to the list of files excluded in Time Machine preferences as well trying tmutil thinlocalsnapshots / 9999999999999999 in the terminal.

Any help is appreciated.
Try this workaround:


Instead of creating a FAT partition, create a APFS partition of the desired size with Disk Utility.
Select the APFS container that contains the new partition and click Erase on the toolbar:


Select MS-DOS (FAT) from the pull down menu, correct the name of the partition as necessary and press Erase:



This will replace the APFS container with a FAT partition.