topic Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5 in ArcGIS Pro Questions

Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

MollyJackson — Tue, 10 Jun 2025 23:44:57 GMT

Last week I logged a bug with ESRI (or so I thought). With the upgrade to ArcGIS Pro 3.5, I am no longer able to use some of the templates and schemas we regularly use, as the Define Projection tool no longer works on datasets with undefined coordinate systems and returns Error 000146.

We use a number of empty geodatabases with undefined projections (some we've designed and some we've received from clients such as the FAA and the US Navy) when beginning new projects. Some of them are complex and contain domains and rules. The first step in this process is to assign the project's coordinate system. Now, with the advent of Pro 3.5, we can't do that any more.

Although I was initially told that this was a bug (BUG-000176807), and others have had the same issue, I was later informed that it is a "Known Limit" instead, with no plans to fix it. Here's the explanation I received:

"These are the public explanations provided by our development team:

"Geodatabases are not designed to allow changes to the coordinate system after a feature dataset or feature class has been created. In earlier versions, it was possible to change the coordinate system of a feature dataset, but this was actually an unintended behavior. Starting from ArcGIS Pro 3.5, this loophole has been intentionally closed to prevent issues.

The reason behind this is that the coordinate system plays a crucial role in setting important parameters such as the spatial domain (range of coordinates), XY/Z/M tolerance, and resolution values. If a coordinate system is left undefined initially and then set later, those spatial properties might not align properly — which can lead to data integrity problems."

I’m truly sorry that you’ve had to encounter this issue.

There is currently no official workaround provided by our development team. That said, after discussing this internally, we would like to suggest the following alternatives for your consideration:

Export the features and assign the correct coordinate system during the export process, or
Continue using ArcGIS Pro 3.4, where the previous behavior is still allowed.

To clarify, in ArcGIS Pro 3.5, the Define Projection tool cannot be applied to a feature class with an Unknown Coordinate System. It can be used if you are specifying a known coordinate system, such as changing from NAD 1983 Colorado to NAD 1983 Virginia — but only when the dataset already has a defined system."

So for now, I've reverted back to ArcGIS Pro 3.4.

Am I nuts for finding this unworkable? It seems to me that as GIS professionals with full awareness of the limitations of undefined coordinate systems (I nag my co-workers to define EVERYTHING), we should at least have the choice to maintain and work with them. As it stands now, I will have to maintain an empty "template" or schema with an improperly defined coordinate system and THEN change the projection using Define Projection tool. I'd much rather start with an undefined coordinate system.

But I'm open to arguments and suggestions.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

RyanUthoff — Wed, 11 Jun 2025 13:31:42 GMT

I'm just......confused by this "issue" along with Esri's response. Per Esri's documentation, it literally says the Define Projection tool is "intended for datasets that have an unknown or incorrect coordinate system defined." But you're saying that Esri said that the tool is not intended for datasets with an unknown coordinate system. That doesn't make sense, because isn't that the point of the tool?

I'm not sure if I'm missing something, but that just doesn't make sense to me. I'm not sure if you've already closed your case with Esri support, but I'd push back and state that their documentation explicitly states that what you are wanting to do is possible per their documentation.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

RichardDaniels — Wed, 11 Jun 2025 15:53:20 GMT

If we are talking about a classic ArcSDE type of Geodatabase that lives on a server, defining the projection details is part of creating the database itself. AFTER the database is created one loads or adds Feature Classes and tables to the database. Perhaps that is the issue here, you are talking geodatabase creation vs. Feature Class? Workflow could be create empty Geodatabase with the desired end-state parameters, then prepare your feature classes as desired then import or do a Project command with the Geodatabase as the output folder to transform the FC's into the desired projection definition.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

MollyJackson — Wed, 11 Jun 2025 16:36:15 GMT

To help clarify the problem, I'm going to present a concrete example. We do a lot of airport mapping--both feature mapping and obstruction analysis. The FAA developed a complex file geodatabase to reflect the data structure required by the governing circular AC150/5300-18B. The geodatabase contains 11 datasets with a huge number of feature classes stored in them. Each feature class has a large number of attributes, many of which are governed by domains. The datasets in this geodatabase have no defined coordinate system, as the geodatabase is used all over the country.

The first step we take upon working with a new airport is to define the coordinate system for all the datasets before we begin populating them with data. With the upgrade to ArcGIS Pro 3.5, we are now unable to define the projection on those datasets, since they are undefined. It just generates an error.

Other than remaining in Pro 3.4 indefinitely (obv. not a solution), the only workaround I can see is to use a prior airport geodatabase from a previous job with an incorrect coordinate system and then define the projection. Again, I would much rather start with an undefined coordinate system than just defaulting to WA State Plane North (or whatever) as a starting point every time.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

MollyJackson — Wed, 11 Jun 2025 16:39:14 GMT

Yes, I am saying that the tool no longer works on datasets with unknown coordinate systems. It works on shapefiles but not datasets within geodatabases. It doesn't make sense to me either.

The tech support I worked with was great, and it sounds like this problem originates with the development team. I appreciate the suggestion to push back and sent an email this morning.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

RichardDaniels — Wed, 11 Jun 2025 20:16:45 GMT

Define Projection is not the same as the Project Command. The fact the development team does not know this is problematic for a GIS software company.
This needs to be escalated and ALSO submitted as an 'Idea' for new development. Having a Define Projection Tool within ArcGIS Pro that does not actually allow you to define a project is by its very nature a BUG. Failure of their design team to understand GIS workflows should not be a reason to refuse to implement a basic feature of ArcInfo, ArcView, ArcGIS Desktop, and ArcGIS Pro.

Geographic data is provided by many organizations without proper supporting projection files (i.e. prj files). This often happens during GPS data collection and integration with other providers such as multiband raster data, AutoCad and Bentley Products. That is why Define Project exists.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

RyanUthoff — Wed, 11 Jun 2025 19:29:58 GMT

I would like a little clarity from Esri regarding this statement:

"The reason behind this is that the coordinate system plays a crucial role in setting important parameters such as the spatial domain (range of coordinates), XY/Z/M tolerance, and resolution values. If a coordinate system is left undefined initially and then set later, those spatial properties might not align properly — which can lead to data integrity problems."

Wouldn't you expect to see more data integrity issues when using the Define Projection tool on a known coordinate system as opposed to an undefined coordinate system with no records in it?

Edit: One last thing. ArcGIS Pro error 000146 states that the "Define Projection tool works with a dataset that does not have any coordinate system." But that directly conflicts with Esri's response to you, stating that "Define Projection tool cannot be applied to a feature class with an Unknown Coordinate System."

Either there is a misunderstanding somewhere, or the documentation needs to be updated to reflect that the Define Projection tool cannot be used on unknown coordinate systems.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

Joshua-Young — Wed, 11 Jun 2025 20:07:51 GMT

I do not understand Esri's response. If the issue is the spatial tolerances, why not have the Define Projection tool clear out those values when the tool is executed and have a warning that is what will happen if you run the tool. Another option is to leave the spatial tolerances and produce a warning that those values do not fit the applied coordinate system.

I really do not see how any of that could be a problem for empty features and tables.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

Joshua-Young — Wed, 11 Jun 2025 20:14:06 GMT

This is more a work around than a solution, but it might be worthwhile to create a simple Python tool that loops through the template geodatabase from the FAA and exports the contents to a new geodatabase setting the projection as it goes. The only inputs would need to be the input geodatabase, output geodatabase, and the projection for the output geodatabase.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

MollyJackson — Thu, 12 Jun 2025 21:57:55 GMT

An update: it appears that I can't use "Define Projection" on any previously projected data. If my dataset or feature class are undefined OR defined, I can not use "Define Projection" to redefine the projection.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

ChristalHigdon_USFS — Thu, 12 Jun 2025 23:16:33 GMT

Yes, we use this in a python scripted build process to migrate to Parcel Fabric. We take an empty gdb and change the "incorrect" coordinate system to the correct one after the copy. It is blank of any data but has a complex structure with relationship classes and related stand-alone tables. This is a huge "bug" from my perspective and a blocker for going to 3.5, which we need for the enhanced attribute rule functionality. The "proper" way to change the projection is to use the Project tool, which leaves behind much of our data. Maybe that is the "bug" in 3.5. I am trying to open an Esri case on this myself but have to go through the proper channels in my organization.
GDB before using Project, with 'incorrect' coordinate system:

After using the Project tool to 'correct' the coordinate system:

Some of the relationship classes made it through, some did not - even the out of the box relationships inherently created by creating the Parcel Fabric geodatabase. The related tables also did not come through.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

RTPL_AU — Fri, 13 Jun 2025 01:35:49 GMT

Hi @MollyJackson, everyone.
This type of thing directly intersects my Idea for Esri to change the release approach of Pro. Please have a look and upvote if found agreeable.
https://community.esri.com/t5/arcgis-pro-ideas/change-pro-development-to-use-a-more-conservative/idi-p/1547856

I have upgraded to 3.5 to get bugfixes for severe issues in earlier versions. In my opinion, bugs should be fixed in the version they occur and and having a long term support version will see that it happens for a decent period of time.

Breaking features such as these MUST be in a feature release version, not a stable/LTS version, so that we can decide if we want bugs fixed or need a shiny new feature. There are already a couple of issues in 3.5/3.5.1 that have been marked as 'fixed' in 3.6!!

I have experienced this issue the other day but I don't do the undefined > defined thing often enough to not realise it wasn't me making a mistake.....

I can't remember this "Loophole fix' getting a mention in the Release Notes?

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

ChristalHigdon_USFS — Fri, 13 Jun 2025 15:25:44 GMT

I searched through the 3.5 release notes and saw no mention of this 'loophole fix'. It really throws a wrench in my workflow, using it as described in the Help Docs to correct and incorrectly assigned projection.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

MollyJackson — Thu, 26 Jun 2025 17:39:02 GMT

After two cases with support services, I've basically been told there's nothing they can do, and I should submit my request to ArcGIS Ideas. So here it is. The more kudos an idea gets, the more visible it is to developers:

https://community.esri.com/t5/arcgis-pro-ideas/allow-define-projection-to-work-like-it-used-to/idi-p/1627343

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

cmathers — Wed, 02 Jul 2025 18:10:31 GMT

I'll reply here but put the same on the Idea. The workaround I will use for this since we apparently have to use a workaround now is:

Export the template FGDB to a JSON with the Generate Schema Report tool.
Edit the spatial reference of each item with python.
Convert the Schema Report to an XML Workspace with the Convert Schema Report tool.
Create an empty FGDB.
Then apply that to a new FGDB with the Import XML Workspace Document tool.

"spatialReference": { "wkid": 102660, "latestWkid": 2238 },

That will appear in every dataset included in the Schema Report. Grab the wkid values from the spatial reference object you want to change to and swap the values throughout the file.

Parameterized as a tool in a toolbox the spatial reference parameter would present you with the normal projection picking GUI. You could skip a step by going straight to a XML Workspace Document and editing that but I hate parsing XML in python, JSON is easier to deal with to me. Its a new development burden placed on the end users but that shouldn't be more than a couple dozen lines of code. A lot of the heavy lifting is done by existing toolbox tools available at all three license levels.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

ChristalHigdon_USFS — Wed, 02 Jul 2025 21:57:35 GMT

Thank you for this helpful workaround. I will give it a try but generally going to/from XML Workspace Document with a Parcel Fabric dataset doesn't work well, for whatever reason. Worth a try since Esri killed our years-long established and well-working workflow of Define Projection to correct an already defined projection on a dataset.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

cmathers — Thu, 03 Jul 2025 13:06:30 GMT

I knocked this together. It works as a script tool in a toolbox but for some reason ignores the overwriteOutput environment setting which is irritating. Didn't test if it does the same in a notebook. If you make a tool from it and set the sref parameter to look for a spatial reference you get the nice GUI to pick which one you want. This does not carry over data though, Schema Reports are just the structure. It might need to be tweaked to work in a different environment, I wrote it quickly and tested it on a single database. Instead of parsing the JSON and searching for the spatial references I just search the text of the file with regular expressions for the lines with 'kid": number' and swap in the new wkid for that number.

import arcpy, os, re def script_tool(inFGDB, sref, outLoc, outName): arcpy.env.overwriteOutput = True projobj = arcpy.mp.ArcGISProject('CURRENT') if outLoc == None: outLoc = projobj.filePath arcpy.management.GenerateSchemaReport(inFGDB, outLoc, outName, 'JSON') wkid = sref.factoryCode with open(os.path.join(outLoc, outName + '.json'), 'r') as schemaFile: schema = schemaFile.read() schema = re.sub('''(?:kid)" ?: ?(\d*)''', f'''kid": {wkid}''', schema) with open(os.path.join(outLoc, outName + '.json'), 'w') as schemaFile: schemaFile.write(schema) arcpy.management.ConvertSchemaReport(os.path.join(outLoc, outName + '.json'), outLoc, outName, 'XML') arcpy.management.CreateFileGDB(outLoc, outName) arcpy.management.ImportXMLWorkspaceDocument(os.path.join(outLoc,outName +'.gdb'), os.path.join(outLoc, outName +'.xml')) return if __name__ == "__main__": inFGDB = arcpy.GetParameterAsText(0) sref = arcpy.GetParameter(1) outLoc = arcpy.GetParameterAsText(2) outName = arcpy.GetParameterAsText(3) script_tool(inFGDB, sref, outLoc, outName)

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

javalos — Mon, 11 Aug 2025 18:33:07 GMT

I am also finding this incredibly frustrating. I am using the Tax Parcel Data Management Solution to create a parcel fabric for my Equalization department, but I can't get passed a Task step THEY created. The GDB they include for editing is undefined** and you have to set your spatial reference, but because of this, it doesn't work. It instructs me to use Project instead and copy the dataset. Why close a loophole you use as a step for publishing Solutions?

** It is actually defined, it's just in WGS1984 Web Mercator. Our datasets are in the South FIPS Michigan projection. It's just frustrating. Using Project like they suggest DOES NOT copy over attribute rules OR relationship classes, so you have to go through each feature class one-by-one to re-assign those rules. This is unacceptable for a pre-built Solution.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

javalos — Mon, 11 Aug 2025 15:11:36 GMT

Thank you for posting this. I thought I was going nuts.

Re: Unable to define projection on undefined coordinate system in ArcGIS Pro version 3.5

RichardDaniels — Mon, 11 Aug 2025 15:14:17 GMT

The ability to define a coordinate system is a fundamental 1st step in creating any dataset. I discussed this issue with the ESRI Coordinates team at the User Conference, that being stated this is what happens when you higher programmers who can't spell 'GIS' and given them veto authority over the GeoScientists in the room. Breaking a tool that has existed since ArcInfo 9.0 without appropriate error messaging shows they were not doing regression testing. A user should not have to come 'HERE' to see why the DEFINE command failed.