This is a question based on an error message, but also is meant to gain more insight about working with topologies. I've created a feature dataset with several road feature classes (I'll call one layer_to_append_rows_to) , and am comparing them to an older version of those datasets (old_roads) outside of the feature dataset, using a topology to help spot and eliminate gaps in the roads. I am using ArcMap version 10.2.2, and when I attempt to append selected roads from old_roads to the layer in the feature dataset, it spits out a
999999: Error executing function message
"Objects in this class cannot be updated outside an edit session [layer_to_append_rows_to]"
You also cannot delete data from the feature class while it has a topology. So I'm curious if anyone knows why you cannot append or delete data in feature classes while they have a topology based off of them - is it a legitimate error/unacceptable process within the Feature Dataset/Topology functionality or is it something occurring because the feature dataset or topology was not created correctly? I was able to create a layer from selected features in old_roads then merge layer_to_append_rows_to without errors, but that creates a new layer outside of the feature dataset.
If that was unclear, processes in ArcMap went as followed:
1) add old_roads to layers, contains road segments
2) create feature dataset
3) import table layer_to_append_rows_to, which has gaps with missing roads
4) create topology based on "no dangles" rule for layer_to_append_rows_to
5) add both topology and table in feature dataset to layers
6) identify gap to be filled, select road segment from old_roads
7) use append tool with NO_TEST, old_roads selected rows as input, layer_to_append_rows_to as output
8) see error message
Any insights would be much appreciated.