Manually renaming files or saving them with hidden extensions (like project.std.txt ) will confuse the engine.
# sketch: parse JOINT COORDINATES and MEMBER INCIDENCES to check references # open file, find JOINT COORDINATES block, collect IDs # find MEMBER INCIDENCES block, collect node references, flag missing IDs This Is Not A Valid Staad Command File
Right-click your .std file and select (or any plain text editor like Notepad++ or VS Code). Manually renaming files or saving them with hidden