APFS Container Resize error code is 49153 in High Sierra
This is how I sorted the error


Reboot the machine
Go into the 'Time Machine' pane of the System Preferences
Right/Ctrl click the Time Machine drive icon
Click 'Don't use {drive name} for Time Machine'
Run tmutil thinlocalsnapshots / 9999999999999999 for the last time in Terminal
Resize the disk.