Adding Slope to Pipe routing AFTER the pipe route is done!

Hi all, i would like to ask how can we add a slope to a pipe segment after i finish that pipe route. 

To be more specific, i finish a pipe route a few months ago, without any slope. My client just contacted me a few days ago, stating that they want to add a slope to a pipe segment somewhere in the pipe route.

So this is what i have done: I went into the edit mode, delete the constrains that make that pipe segment fully defined. However, there's an error keep popping up: "slope cannot be created, adjust the slope angle, section length or weld gap and try again". How can we resolved this?

I want to add slope to the pipe segment in between the 2 45 bend as shown in the image below.

Thank you!

SolidworksRouting