I'm having trouble removing the separator line on a page.

I have tried to edit the template I'm working on, but the black vertical separator between columns seems impossible to delete.

The options when having this separator selected are 'greyed out'.

I have added a screenshot of the problem I'm referring to.

As you can see I have selected the separating line. -But it simply cannot be edited.

-Has anyone else got this problem, or am I completely overseeing something?

Thanks!