When creating a new Email Template you can enter some text into both subject and content fields and then save and it will save. However if you change the body content to document - but then change it back to plain text or anything else the template will no longer be able to be saved.
The user will get the error
`Failed to validate property Content: Content is required`
Even if the plain text content field has a value this will occur - the error is that when the user switched to document they did not attach a document and the archetype is still looking for it.
Steps to replicate:
1. Create a new Email Template
2. Enter something in both Subject and Content leave the type as plain text.
3. Save it.
4. Edit the template
5. Change the subject type to document and then change it straight back to plain.
5 You will find you get an error when you now press OK and will need to press cancel and lose any changes you may have made