We found an issue with the original 5.8 Windows installer, it was missing the Profiled Lens Correction (Lensfun) database, so there is now a new installer which includes this database. If you downloaded RawTherapee 5.8 for Windows previously, please download the new build and re-install.
The macOS build is now ready.
Head over to the Downloads page to get the builds.
2d6f127598ef9a3d36a86657ac53c81b1957b6d9ae97fef1fadd8757f82aa915 RawTherapee_5.8.exe (2020-02-06)