Hello, I am trying to add new / custom linestyles to the Draftsight that I just installed. It does not allow to edit existing MM.LIN file (locked, allowed to change it only on the duplicate), and does not activate other .LIN files when trying to load them through the Format > Line Style menu (I do find files through the browser, but they are inactive / not available for selection) 

Please kindly help. 

I use Draftsight Standard. Can it be an issue?