I want to import my tool holders via an ISO13399 standard step.
to do this, I downloaded my file (3D DETAIL) from the SECO website (https://www.secotools.com/article/p_10229678?pf=true&entryPoint=ProductTree) and then tried to import it into the standard element collabspace.
I made the import attempt using the STEP_ISO13399 format (*.stp) 
but it didn't work; I got the following error message.
why this error?
 

On the site, it's clearly stated that the downloaded file “3D DETAIL” corresponds to a 3D in .stp format in accordance with standard 13399 (support for 3D simulation and collision testing).
 

could you help me?