This is what it reads but I do not understand why.
[2016-10-10 17:40:20][INFO][mode: settings][stage: integrity
check][step: Settings Step]: started100% [============================] Remaining Time: 1 sec
[2016-10-10 17:40:20][ERROR]: Integrity check failed due to
"core_config_data" document does not exist in the source resource
[2016-10-10 17:40:20][INFO][mode: settings][stage: integrity
check][step: Stores Step]: started100% [============================] Remaining Time: 1 sec
[Migration\Exception] Integrity Check failed migrate:settings
[-r|–reset] config
Best Answer
My error was that I did not have a source prefix defined in config.xml file.
I had to change
<source_prefix />
to<source_prefix>gfit_</source_prefix>