This is a known issue that will be fixed in a future release of BT Phobos. For now, please use the following workaround.
- Close all instances of Ableton and Phobos
- Search for a file named Phobos_Spitfire_Audio_Harmonic_and_Melodic_Phobos_Organ.zpreset
- Rename this file to Phobos_Spitfire_Audio_Harmonic_and_Melodic_Phobos_Organ.zpresetdisabled
- Restart Ableton and Phobos will no longer default to Phobos Organ when loading a project.
One caveat is that Phobos Organ will no longer be available, though this will be restored in a future release.