Graph.js:96 Uncaught Error: Entity n9485242671 not found
at Dr.entity (Graph.js:96:13)
at almost_junction.js:195:28
at Array.forEach ()
at x (almost_junction.js:193:15)
at l (almost_junction.js:46:33)
at N (validator.js:591:22)
at Array.forEach ()
at w (validator.js:579:25)
at validator.js:693:24
at validator.js:762:32

@cbeddow and I sat together for a bit on a vid call and couldn't repro- but while trying to repro we mapped some sidewalks that crossed existing parking lanes/ways to get validations to crop up. The connection warnings resolved quickly.

I posit that perhaps an unrelated bug caused the UI to start acting squirrelly (sometimes when we stack trace, the UI can continue working mostly, but start behaving very strangely).

Sure enough after enabling/disabling mapilllary, then reloading the page, we were greeted with the above trace entity n9485242671 not found.

Opening the 2.0.3 code in the browser (with source maps) gets me to the following line in almost_junction.js:

    function findConnectableEndNodesByExtension(way) {
      let results = [];
      if (way.isClosed()) return results;

      let testNodes;
      const indices = [0, way.nodes.length - 1];
      indices.forEach(nodeIndex => {
        const nodeID = way.nodes[nodeIndex];
        const node = graph.entity(nodeID);         <-- This guy 

Okay, so the whole issue here was : we reworked/rethought the way we saved changes to the local base graph in the application storage. This meant that certain features in the base graph were NOT getting saved.

If you edited pre-existing features, refreshed, and then clicked 'restore my changes' really fast (before the OSM data could load) then it could result in this graph error occuring, which could cause undefined UI behavior.

Strongly suspect that this is the underlying cause for #1048 and #1049