The possible reasons and solutions for this error are:
Your CMS software is not installed.
Please, install your CMS and restart your migration.
Your CMS type is not supported.
Your CMS is heavily customized.
Therefore, requires an individual approach, and CMS2CMS may be not the right tool for this job.
Your config. file is not found
To find out the default site configuration file location for your CMS, please check this FAQ: https://cms2cms.com/faqs/where-is-my-configuration-file-located/
Please, use Support Chat button in your dashboard to get live help or contact us at firstname.lastname@example.org.