Version 4.2.1 was released Feb 18, 2019 as a minor release to 4.2.0. The major changes in this release fix several problems with using the built in editor to create new models and to bring the NXcanSAS reader into compliance with the final published specification. A few other enhancements and bug fixed were also introduced such as cleaning up the resolution section of the fitting page GUI, increasing the max size range allowed in the corfunc analysis, and adding the incomplete gamma function to the C library. Try it now!
For more details, please see the Release Notes which are now available from the program Help.