What to do about “[Shape_STLength__]” Errors?

Oh boy….
Database error: The field is not nullable. [Shape_STLength__]. The geometry is not Z-aware.

TL;DR
That field shouldn’t be there, you can safely remove it. I wrote a quick script to do so here: https://gist.github.com/morehavoc/3e86f535bf204b040ee2

Now for the full story…

It took me a bit to figure this one out, I thought “Hmm, that looks like an Esri field, why would I be populating the Length from my javascript app, shouldn’t the server take care of that for me?” As it turns out I was wrong, that is not an Esri field… but in my case it was caused by Esri.

For me the field was in a feature class that I had created via a Python script using another feature class as a template; that was the issue. Esri, being so helpful, decided to convert the Shape.STLength() field into Shape_STLength__ and to top it off, make it required as well. The field Shape_STLength__ has no use, other than to cause trouble. The Shape.STLength() field is not actually a real field, it is a alias created by Esri to get the length of the geometry, handy right!

Once I figured out that was the issue, I was able to remove all of the Shape_STLength__ and Shape_STArea__ fields using a python script (making sure to shut down my services first) and all was well once again.

You can check out the python script here: https://gist.github.com/morehavoc/3e86f535bf204b040ee2