Windows Security often blocks .lsp files downloaded from the internet.
Since this is a community-created script, it is hosted across various CAD forums and developer repositories: autocad tlenlsp download work
The (Total Length) routine is a popular custom AutoLISP script designed to calculate the cumulative length of multiple selected objects—such as lines, arcs, and polylines—within AutoCAD. Since standard AutoCAD does not have a single native command to sum the lengths of diverse selected entities in the Properties palette, this tool is essential for tasks like irrigation, pipeline, or electrical design. How to Download and Load TLEN.lsp Windows Security often blocks
First, let’s correct the search term: is almost certainly a typographical error. The correct file is tlen.lsp . The “LSP” stands for AutoLISP , the scripting language of AutoCAD. How to Download and Load TLEN