Append error in ArcGIS Pro 2.x

[StayMappy]

I have been using the Append tool and when I have a polygon selected to Append, the Append tool runs the Append on all the polygons in that layer giving multiple copies of the same polygon. I have read that the Append tool will only append to selected features but this is not the case when I am using it. I have tried this with the stand alone tool as well as in a Task. arcgispro append arcpro

[DanPatterson_Retired]

Append—Data Management toolbox | ArcGIS Desktop appends one feature layer to another

Merge—Data Management toolbox | ArcGIS Desktop combines two feature layers to form a new feature layer.

So when you say you are using the 'append tool' can you explain if these are the tools? or are you trying to combine two geometries when creating features or something else

[StayMappy]

Yes I am using the Append tool. I am appending newly created polygons to an existing dataset. 

[DanPatterson_Retired]

I haven't seen that behaviour unless you are incrementally appending from one featureclass to the original.  

Try the merge approach to produce an incremental version of the process (a new name each time of course) to see if that can at least alleviate any duplication.

I wouldn't rely on appending a selection from one featureclass to an existing, if that is what you are reporting.  

[David]

A colleague experienced that exact same behavior. I tried to duplicate the error using ArcGIS Pro 2.2, but the append works as expected, only appending the selected features. I recommend updating to the latest version and trying the append again.

[StayMappy]

I tried this and unfortunately I am still getting the same error. I have run it in a Task as well as a stand alone tool and they both do not honor my selection and instead append everything in that layer.