Open a level that contains instanced meshes will crash the editor. Per the users description, the level must have had lighting built and then another level loaded or the editor restarted. Once the original level that contains the instances is reopened, it will crash the editor. (No crashreporter window will be present)
I couldn't reproduce this from scratch but it is reproducible in the attached project that the user provided.
Possibly linked to JIRA
UE-10157 which could not be reproduced.
1. Go to (See Comments for file path) and download 'ReproProject.zip'
2. Unzip & open the .uproject file
3. Once loaded, go to the Content Browser > Maps > Open 'InstancesMap'
Results: The editor will crash without a crashreporter window
Expected: To be able to load the level without crashing
No call stack (Crashreporter window never appears)
Head over to the existingAnswerHub thread and let us know what's up.