When Ram Connection for RAM SS is launched the program pulls the load combinations from Ram Frame Steel - Standard Provisions. Combinations from the Ram Frame - Steel - Seismic Provisions mode are also imported when that mode is current (green light for model status).
The user can override this with the Load Combinations ribbon menu dialog box launcher as indicated below.
If this option is unchecked, then Load Combinations need to be added within Ram Connection using Add/edit or Generate in the same ribbon menu.
Since the program is trying to pull the combinations from RAM Frame, this error will occur for all gravity models that do not have any Ram Frame combinations defined. To proceed in such a model, uncheck the option to "Include RAM Frame - Steel Provisions Mode load combinations as noted above, then manually define or generate new load combinations.
Refer to https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/8105/ram-connection-capabilities-and-modeling-faq#load_case
Depending on the version of Ram Connection, you might encounter one of these error messages:
The first issue pertains to the length of the Load Case IDs, In early versions of Ram Connection this was limited to 5 or fewer characters, so the Load Case names in RAM Frame needed to be short.
The second pertains to load case names with unexpected symbols in the name. For example, if the underscore character (_) is sed in a load case name in Ram Frame this can cause Ram Connection to misread or truncate the load case names.
Both of these specific issues have been addressed in the current version or Ram Connection (13.04.00.183 as of this entry), but if you encounter such a problem, try simplifying the load cases names in Ram Frame - Analysis mode.
RAM Connection Capabilities and Modeling FAQ
RAM Elements Load Combos [FAQ]
Ram Connection Seismic Provisions Settings
Connections for Gravity Members are Designed for Zero Force
Troubleshooting Errors when Assigning Connections