Why cant I delete certain curtain grid segments?

[JB27]

Had this problem 11 years after the last post, in Revit 2019. The solution here still works--once I set the type parameter for vertical spacing to "none" I was able to delete the unused grids.

[jbernier373584]

I was able to overcome this same problem by changing the Vertical and Horizontal Grid layouts to "None" in the type properties... I was afraid this was going to delete the custom grid layout I had created, but it didn't. Now when I select the grid line to remove a segment, Revit cautioned me about deleting a grid line... but it appears that the "system" grid lines that are made by determining vert/horiz divisions initially made duplicate grid lines (or maybe somehow I did when I customized it?) and that seems to by why I couldn't remove the segments before. Deleting the duplicate grid line then allowed me to fully access the segments. Hope it works for you!