I used this test build with raw files from a Fujifilm S200 EXR as well, and worked so far that RawTherapee 5.7 could work with the content. But there is a known bug: The encoder class changed during the upgrade from Qt v4 (JPEG) to v5 (JPG), truncating the generated DNG file prematurely. So other software complains about the broken DNG. Another test build, if not even a release v0.6, would be helpful.