Lline color

[Cherokeedesign]

I have Structure version 2005. I am trying to learn to use the program with the included "on the CD" training manual and the on disk training model files. The model I'm making is a multi-floor building that is created by the student using the one level model file which shows only the exterior walls and columns. Training file is named i_structure_CMS.rvt.

I have created one floor framing and slab and then they are copied to the 6 other floors. Some of the top floors have some areas changed to eliminate part of the structure. After doing this I decided to change the floor slab where I used straight ling segments instead of the radius line to form a portion of the slab. I deleted the slab and proceeded to add the lines to form the edge of the new slab with a circular radius.

These new slab edge lines did not become "black" lines; they are green. When I click on the lines they change to red color but when I select the "slab" in the modeling tab, set properties of the slabs and finish the operation; nothing happens. A error message pops up when I click on "finish".

Questions:
Why is the slab edge line green instead of black? (Model window is white.)
Is this why the slab making won't work?
Anyone have a suggestion to correct this error?

Thanks for any reply.