Can you help me, I do not know what to do. I made a s7 300 LADDER DIAGRAM when I saved it, the network 1 became STL. I already re-install the software but same thing happened. Thank you for your help :) it is really appreciated

Can you attach that software in order to test it?

Best regards,

Hristo Mihalev

LAD code is convertible STL but vice-versa is not true. This is because Step 7 by itself uses many noncomulsory STL commands which helps to display the code in LAD, and if you happen to delete/modify these non compulsory STL commands then code will not go back to LAD. Also going back to STL will get effected if you have used TEMP variable which was actually being used by LAD.

You have to understand the code and re-write it in LAD, re-installing Step 7 wont help you.