GEOPAK Drainage - Longitudinal Slope Source Unable to Calculate from Reference PGL

I have a project with multiple alignments and profiles and the GDF is able to calculate the logitudinal slope source using the reference PGL for all alignments/profiles except for one.

Are there some common things to double check within the GDF, GPK, stored profile (such as station equations or profile gaps), etc.?

Any ideas/help would be appreciated!

Thanks,

Bryan

GEOPAK SS4 08.11.09.878