There was no file database conversion required between version 16.00.00.28 and 16.01.00.20 (which is atypical for RAM Structural System versions). A consequence of this is that if a model is saved in version 16.01, then opened in version 16.00 it will appear fine, but saving changes to the file in v16.00 will corrupt the file.
See this for details: https://communities.bentley.com/products/ram-staad/w/structural_analysis_and_design__wiki/42880/saving-version-16-01-models-in-version-16-00-causes-file-corruption