New Email Template save failing "404 error: Page not found."

[cci1]

After I create a new email template and hit 'Save Template' it returns with a 404 page not found error. Checking the templates list after that shows it didn't save. "Preview Template" also results in the same.

Anyone know how to fix this?

Magento 2.1.7  

Thanks

[cci1]

Bump

[LivePure]

This happened in my build. I asked my hosting provider to help me troubleshoot. They said it was a "permissions" problem and fixed it. I'm sorry I don't know exactly what they did... but check with yours and see if they can help you. Good luck!

[cci1]

I forgot to update this post.  Our Hosts mod_security was getting tripped by this, they added an exception and it works fine now..