"No data received" error when a comment is submitted

I got an e-mail from someone saying that whenever they attempted to submit a comment to my posts, right after hitting submit, they get a “no data received” error.

I tried it myself and logged out and attempted to comment and got the same error.

I have tried:
– updating to the latest version
– disabling plug-ins
– checking dicussion settings to see if comments are enabled
– switching to a different theme

None of these have worked and I still keep receiving the same error.

My website is: Elliecee.com

Any help would be appreciated. Thank you!