Message/emails To Customers Fails

Message/emails To Customers Fails

Hello,

Regarding my issue with ending emails to customers, when Igo to Dashboard > Orders > Click on an Order > Notes Section > Message,

When I want to send a message and enable "Send as an email to the customer", this error pops up:

A JSONObject text must begin with '{' at 1 [character 2 line 1]


To summarize, my website's email sending service to customers when they order and pay, and the order has been confirmed ans shipped does not work.

Please let me know how it can be fixed. I asked fo this to be fixed a few times within the last few weeks. The problem still exists.