Cannot delete unlocked grid lines from a curtain wall

[IMCornish]

For some reason, a curtain wall I have created, has assumed two vertical grid lines that I do not want.  I have unlocked them but I cannot deflate them and have no idea why this has happened.  See the screen capture below

I would be very grateful if someone can help with this, thanks.

 

[Anonymous · Accepted solution]

Rule based settings in the curtain wall?

[BDMackey]

I have a standard curtain wall type "Undefined" when I start unpinning parts of a curtain wall I will change to this type, where there isn't any grid spacing, mullion or panel types defined.  One reason for this is because there is a bug with in Revit that when certain things happen to that wall it may default a curtain wall back to it's type property setting, in essence re-pinning all of the components back to their defaults.  This is also why it won't let you delete it, as @Anonymous pointed out above.  If nothing is defined it can't default back and you can remove all of the curtain grids