Define Projection crack-down

[AustinStreetman]

With ArcPro 3.5, ESRI has cracked down on letting us define the projection on a feature class that has a projection. We have been importing an existing schema from an XML and then using Define Projection in a model to redefine the projection for the new project. In 3.5, this no longer works. We tried it in arcPy as well. 

This seems like an unfortunate level of hand-holding. ESRI should trust users to know when it is appropriate to redefine a projection. 

[Nick_Creedon]

@AustinStreetman I am not in Version 3.5 yet, this doesn't seem like this is intentional. I would reach out to support about your issue. As long as the tool is in ArcGIS Pro you should still have the capability to change the projection.

[RyanUthoff]

I am not able to replicate this behavior in 3.5. Per the 3.5 documentation, it states: "when a dataset with a known coordinate system is input to this tool, the tool will issue a warning message but will run successfully."

I don't think Esri intentionally took away that functionality. I suspect it's just a bug. You'll probably have to reach out to support and see if they can reproduce the issue on their end.

[DarylHochhalter]

Yes, but also states it won't work on a DS with an existing feature class.

[DanPatterson]

If you compare the 3.5 to previous versions at

Define Projection (Data Management)—ArcGIS Pro | Documentation

you will notice that there are new restrictions.  I can't tell from your code and the files whether this is what you are running up against.  Have a look and compare to your previous version using the "Other versions" toggle

[DavidSolari]

Comparing 3.5 to 3.4 in detail, I don't see any new restrictions, there's just more clarifications for why you can't run the tool on EGDB or Feature Dataset classes (as well as workarounds).

@AustinStreetman if you try to define projections for some troublesome data using just the tool interface (no arcpy) do you get a better error message?

[DarylHochhalter]

I jumped from 3.1 to 3.5, it worked in 3.1 for sure. The new 3.5 version greatly reduces the usefulness of the tool. I had to run the same script on a machine that still has Arcmap in order to get it to work on existing data. Nothing short of a ridiculous change!

[DavidPike]

Certainly run the test in Pro GUI or get and print print the actual error.  This could be many different things from switching versions. 

[ChristalHigdon_USFS]

We use the DefineProjection tool extensively in arcpy for a scripted process that we re-run during development and migration into ArcGIS Parcel Fabric. In prior versions (3.4 and earlier) there were no issues. We have Pro 3.5.0 and all of a sudden I am getting an error ("ERROR 000146: Cannot alter the spatial reference"), in both arcpy and Pro/UI Toolbox for Define Projection. I am trying to open an Esri case because this seems like a bug. I think it should still run with warning as it always has if there is already a projection defined. There is no way to set Unknown spatial reference, so what if you make a mistake, or are conveniently using it to set up a new gdb that does not have any data in it yet? 

[DarylHochhalter]

Unfortunately it's not a bug, but an intentional change like the original post indicates!