403 Forbidden error message now appearing


Wordpress plugin working for many months —sends new posts automatically as tweets. No longer woking as of a day or two; receive the following message when a tweet s attempted:

One or more of your last posts has failed to send a status update to Twitter. The Tweet has been saved, and you can re-Tweet it at your leisure.

403 Forbidden: The request is understood, but it has been refused by Twitter. Reasons: Too many Tweets in a short time or the same Tweet was submitted twice, among others. Not an error from WP to Twitter.

the option below is checked:

Switch to http connection. (Default is https)

Using http connection—tried https and the problem persists.