Error Message when Deleting Features in Pro - unknown coordinate system

[dagmarGermonprez]

I have an old shapefile with polygon features added to my map in ArcGIS pro and I encounter several problems, which I think (hope) are all due to the fact that the file has no coordinate system. (I did not make the file myself, always bit tricky)

Anyway I tried to fix this, by going to map properties > coordinate systems, but I seem to only be able to change the coordinate system for the entire map and not just for the layer. Is there a possibility to add a coordinate system specifically to the layer? I tried through the layer properties too, but that did not work out either.

Just to be clear: the data is projected as the other layers in the map, so no problem there, but when trying to edit the layer / delete some features in it, I always receive the message: 'Delete Selected Features failed. The selection contains no editable features. - No edits producing database changes were found." It is still possible that I am doing something wrong - still bit clumsy in ArcGIS I am afraid...

[DanPatterson · Accepted solution]

If you know what the coordinate system is, then use

Define Projection (Data Management)—ArcGIS Pro | Documentation

[BarryNorthey]

The error message is explained here. As noted above, you will likely need to use GP tool Define Projection. 

A coordinate system besides Unknown as set for a Map enables on-the-fly coordinate projection of the layers in the Map to the coordinate system of the Map primarily for proper alignment of the various layers that might have different coordinate systems from the Map. Changing the coordinate system of the Map does not change the coordinate system of its layers. 

[dagmarGermonprez]

Hi Dan and Barry,

I should have mentioned it, but I already tried to define projection before posting on this forum, as I indeed know the coordinate system. But I will give it another try with some fresh energy 🙂

[RichardDaniels]

or you can just create the .prj file manually. They are just text files with a .prj (projection) extension, if your shapefile is named mydata.shp then the prj would be named mydata.prj. 

Example contents of the file at ESRI PRJ File (https://vsp.pnnl.gov/help/vsample/ESRI_PRJ_File.htm)

[dagmarGermonprez]

So I tried again to define projection. In the one file with several layers I got an error message each time. But in a file with only one other layer, it worked out.

Thanks guys! ❤️

[RichardDaniels]

you need to use DEFINE projection tool