There no longer a comment input because the database is linked to a working folder.
This is because the working folder is what is actually linked to your repository not SQL Source Control. Therefore commits are made manually using your source control client from the working folder to the repository and you would use the comment in your source control client
http://documentation.red-gate.com/displ ... ng+folders
In version 188.8.131.52 there was a change made to how the tool is connected to GIT. This involved using a working folder and using your source control client to commit to the repository.
To use the old method of using a config file select custom as the source control system and select the GIT config file.