Initially realize this is not an Error, is just a Warning.
It states that the Load Type G is not implemented for the Springs.
You could get rid of it by unselecting the Spring Elements Series from this load cases.
Senior Technical Support Engineer, Bridge
MSc., Structural Analysis Specialist, Civil Engineer, RM Bridge Enterprise
Bentley Systems Inc.
You can find complete examples and documentation included in the software installation at File/Examples.
Also find tutorials on adding beam section information at the instructions documents by selecting the button Description. At Training Examples\04a Balance Cantilever there is a section Modifications in Modeler and all the Temperature definitions are added to the CS.
At the Top Menu click on Modeler / Cross Section to modify directly the Cross Sections drawings. Geometrical modifications could be made either in Modeler, Analyzer or externally at OBM or in a .tcl programmable ASCII text file.