Did you get the "can't instantiate template" type of error when you are working with the Email template with the CDS connector?
Working with Microsoft power platform MS flow with CDS sometimes you will get a template error. You will not get a solution on that issue but I am explaining to you a workaround on this issue.
Error
Create a flow that will be sending an email through bound action.
Add trigger action in the flow.
e.g. Account on creating,
Create a new record with Email Message,
Set 'From' and 'To' on the Email message,
Now we can put an email body with our design same as the email template body. We can design our email body data using HTML tags in the description field itself.
After this, you can use bound action to sending the email.
Using the above will resolve your issue with the template. The above solution is a workaround for the email template which will get when activities not enabled on the entity. For some of the entities, the Activity will be disabled and not able to enable from the customization that time we can get 'can't instantiate template error'
I hope the above solution will help you to resolve your issue!!
Keep learning new things......!!