The error could be related to:
Using API on the wrong domain/subdomain (www prefix can be relevant).
Temporary Twitter issue.
Make sure your code is passing the valid
For OAuth 1.0a compliance this parameter is required unless you are using xAuth. Currently Twitter supports both OAuth 1.0 and OAuth 1.0a which means we do not error if this value isn't included. It is strongly recommended that applications not using this parameter are immediately updated with support for
oauth_verifieradded. OAuth 1.0a will be enforced soon and applications not using the
oauth_verifierwill fail to complete the OAuth flow.
Your Twitter module may be outdated, please consider upgrading it.
If it's still happening, check the logs for any detailed responses. Otherwise contact Twitter support.