"Oops. Something went wrong" but no missing fields or lists

Reposting this issue because it was marked as resolved but hasn’t actually been resolved:
https://ww.wp.xz.cn/support/topic/oops-something-went-wrong-but-no-missing-fields-or-lists?replies=17

I have a super basic subscribe form on my site, just the email field and submit button:
<input type=”email” name=”EMAIL” placeholder=”Enter your email address” required><input type=”submit” value=”Sign Me Up”>

I’m getting this error any time I try to subscribe a new email address:
Oops. Something went wrong. Please try again later.

* No other fields are required for my list.
* I did not forget to select a list in the form configuration.

Those are the only two possible issues I can find in other threads on the topic, and they do not apply to my situation.

This form used to work until a few updates ago (unfortunately I didn’t catch which one).

I downloaded the dev version of the plugin and checked the logs and got this error:
[2016-01-25 13:44:02] ERROR: Form 19906 > MailChimp API error: This email address looks fake or invalid. Please enter a real email address.

I thought it was just because I was testing with a Mailinator address but I got the same error testing with some real ones.

https://ww.wp.xz.cn/plugins/mailchimp-for-wp/

Please continue with your previous topic: https://ww.wp.xz.cn/support/topic/oops-something-went-wrong-but-no-missing-fields-or-lists?replies=17