Mozilla removed it. This can happen when issues are found during the review of the extension or theme, or the extension or theme has been abusing the terms and conditions for addons.mozilla.org. The developer has the opportunity to resolve the issues and make the add-on available again.
Mozilla jo ju wótwónoźeł. To móžo se staś, gaž se problemy za pśeglědowanje rozšyrjenja abo drastwy namakaju, abo rozšyrjenje abo drastwa jo wuměnjenja za addons.mozilla.org znjewužywało. Wuwijaŕ ma šansu, problemy rozwězaś a dodank znowego k dispoziciji stajiś.