UFPS version 1 is no longer supported and is built for Unity 5.6 - 2018.3. It is not guaranteed to function in Unity 2019.1 and beyond.
Please consider upgrading to version 2 for continued support.
Thank you!
IMPORTANT: ALWAYS REMEMBER TO BACKUP YOUR EXISTING PROJECT FOLDER BEFORE INSTALL For a full list of new features and bugfixes, see the RELEASE NOTES.