The Unblasted Blocks step contains a list of fully drilled blocks.
If charging activity is being modeled in the Schedule, fully charged blocks are set to blasted by default.
Ensure that all drilled blocks have been updated in the Preschedule step.
This step fixes the problem when it has been impossible to model a block that is fully drilled at the start of the schedule but could not be mined yet as it must be charged and blasted first