THE NUMBER OF NON-ZERO MASSES REQUIRED
ERROR : THE NUMBER OF NON-ZERO MASSES REQUIRED = 5
THE NUMBER OF EXISTING MASSES IN THE MODEL = 0
JOB WILL BE TERMINATED.
The error comes up because you are trying to perform Eigenvalue Analysis without having defined masses in the model. Mass properties are a key parameter for dynamic analyses, so you need to define them.
You can convert the self-weight of the structure into mass by going to Structure >> Structure Type, and check on Convert Self-Weight into Masses:
You can also convert loads to masses from Load >> Loads to Masses:
And in the loads menu you can also assign masses directly to nodes.
Technical Support Team