Step-By-Step # 5 : "The data source cannot be reached or its configuration is invalid. Please contact your system administrator."

You need to set up a Shared Workspace to enable this option in the Community Edition of Appian.
Once you log in to the Community Edition environment and select your region, you will be prompted to fill out a survey, which will lead to the creation of a workspace.
After the workspace is created, this option will appear when you create a record.

I am attaching some screenshots for your reference.

You need to set up a Shared Workspace to enable this option in the Community Edition of Appian.
Once you log in to the Community Edition environment and select your region, you will be prompted to fill out a survey, which will lead to the creation of a workspace.
After the workspace is created, this option will appear when you create a record.

I am attaching some screenshots for your reference.

Thank you so much Shubham Aware for suggesting the option. i will try it but it appears the Community Edition site is under maintenance (I am seeing this option since last weekend): Do we know how long does it take to usually ? 

Generally, it will not take much time, but I can see that Appian is working to restore availability. As there is no concrete information, I recommend checking every day, though it will mostly not take much time to restore.

Thank you Shubham. will keep checking. It is still showing under maintenance.

I just tried it and it looks like it is no longer under maintenance. 

Devi Ram Check now.

Yes, it is available now. Thanks

Thanks Shubham. I am able to proceed now. Thanks for your guidance. 

Hi Shubham, 
I have a shared workspace, when I attempt to build out a record type based on a database table (as you show above) I get the error "The data source cannot be reached or its configuration is invalid. Please contact your system administrator." 
Is there anything you can think of causing this error? is there a way to reset my workspace and request a brand new one? 

Thanks in advance!

You might not have proper access to it.
Email communityedition@appian.com with site URL, workspace name, and a screenshot of the error so the CE team can repair or reprovision the workspace

Thanks for the response! I emailed them last week and still have not heard back, not sure if that's standard response time. I'll keep waiting as it definitely seems like it has to do with the connection to the data source which I don't have access to tinker with w/o an admin profile.