why i cannot proceed to advance design concrete, the system direct said ' advance design concrete not found' . why?
Have you installed RCDC included with STAAD.Pro ? Please check the following wikis.
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/47243/advanced-concrete-design-now-included-with-staad-pro-license
https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/40354/which-license-should-i-choose-when-using-rcdc