DSSR Basic does not have the base mutations feature at all. Also note that DSSR Basic is provided AS IS without any warranty of support.
That said, DSSR Basic does include features described in the three DSSR papers (2015 DSSR, 2017 DSSR-Jmol, and 2020 DSSR-PyMOL, all published in NAR) so that reported results can be reproduced. The DSSR Basic manual should function as expected. Anything to the contrary will be considered a bug and will be fixed as soon as possible.
DSSR Pro includes new advanced features, plus
all functionality of 3DNA v2.4, as well as full support. Please watch
the DSSR Overview Video.
Instead of DSSR/3DNA v2.4, you may want to try other software tools such as RNAView, FR3D, MC-Annotate, or Curves+ etc. Please let us know what you find.
Best regards,
Xiang-Jun