During Settings Migration (Magento Migration Tool) –> [ERROR]: Source and Destination documents are not mapped: store, store_group, store_website

Magento 1.9.4 --> Magento 2.4.2-p1

I’ve setup a fresh domain, installed Magento 2.4.2-p1 via Softaculous. I’ve modified config.xml with the correct settings including the source_prefix and dest_prefix of the databases and now when I run the Settings Magento Migration tool via the following command:

php bin/magento migrate:settings
vendor/magento/data-migration-tool/etc/opensource-to-opensource/1.9.4.0/config.xml

I get these Errors:

[mode: settings][stage: integrity check][step: Stores Step]: started
100% [============================] Remaining Time: < 1 sec

[ERROR]: Source documents are not mapped: 

core_store,core_store_group,core_website

[ERROR]: Destination documents are not mapped: 

store,store_group,store_website

I haven’t set up the store, store_group, store_website yet on the new Magentodo I have to do that BEFORE I run the Magento Migration tool? I think there may be an issue with the names of the stores/store_groups/store_websites as on the original Magento 1.9.4 system it has numbers in the names and that is not possible on Magento 2.4.2-p1? Any suggestions on how to proceed?


Updated on July 13th, 2021:

Apparently, this error happens when M1 or M2 use prefix in table names. I have added the prefix in the config.xml file in the following tags and that fixed the problem:

<source_prefix />
<dest_prefix />