WP Ultimo is a brilliant plugin with many important features for creating multisite networks, and many people depend on it.
Unfortunately, the author abandoned the project some time ago for unknown reasons, and the wpultimo.com website became unavailable a few months ago.
However, a community member has created an open-source fork and taken on the heroic responsibility of maintaining the plugin.
The community fork already has a new version with bug fixes, performance improvements, and it no longer requires a license; and we encourage everyone to use the community fork instead of the official WP Ultimo plugin.
If you experience any issues related to WP Ultimo, you can submit your questions or bug reports to the issues page on GitHub.
You just need to install the community fork as a regular plugin and it will automatically replace WP Ultimo, and all the WP Ultimo features are expected to work the same. No changes are required. Our plugin WP Frontend Admin will work fine with the community fork with the same functionality.
* Disclaimer, we are not the creators nor maintainers of this community fork. We just recommend it as an open-source community-driven alternative to WP Ultimo.