anyone has simile problem? macbook runs beta 4 of 10.13.4 always fails at halfway of backup, said "error occurred while copying files". i thought it was TC disk problem, i tried to erase disk by "zero data out", still same error, couldn't even complete the new first backup. tried other macbook which runs 10.13.3, backup works fine. do i have to turn off time machine and wait until official 10.13.4 release?