Error no unsupported masses entered - check densities in seismic definitionhttps://communities.bentley.com/products/ram-staad/f/ram-staad-forum/193033/error-no-unsupported-masses-entered---check-densities-in-seismic-definitionDear all, Error found during the seismic definition analysis. Found the error &quot;no unsupported masses found - check densities&quot; . Kindly help me out from this .en-USTelligent Community 12RE: Error no unsupported masses entered - check densities in seismic definitionhttps://communities.bentley.com/thread/571039?ContentTypeID=1Wed, 26 Feb 2020 15:39:15 GMT6dad98f5-dbc9-4c4d-a9ba-e9da8dc6aa8e:db658ef4-a4a3-4d77-810e-bebac15cde2fModestas<p>You have added the Response Spectrum loading, but did not provide the Mass Reference Load which is used to form a mass matrix for the dynamic response spectrum analysis. You can find some more details about the mass modeling in the STAAD,Pro Help section Technical Reference of STAAD Commands &gt; TR.31 Definition of Load Systems &gt; TR.31.8 Mass Modeling &gt; TR.31.8.3 Mass Model Using Reference Load.</p><div style="clear:both;"></div>