Some of you may have noticed problems where SIRIUS 4.4 GUI did not start without reporting any error.
This might be due to old incompatible configs (.sirius directory) from version 4.0.1. SIRIUS 4.4.21 fixes this problem and now uses a separate config directory (.sirius-4.4). It is now possible to use version 4.0.1 and 4.4.x along on the same system without interfering each other.