Duplicated with:
Chaos Forum crash after merge render setting while IR running.
Chaos Forum Merging objects during IR is crashing Max
Chaos Forum Corona 4 crash.
Chaos Forum 3dsmax + corona 4 crash with IR when merge objects
Chaos Forum 3dsmax Crash when merging scenes
Chaos Forum Corona 4 hotfix 1 Crash
Chaos Forum Max freeze when Importing object or error on modeing plug-ins
https://forum.corona-renderer.com/ Max crush merging objects to scene during interactive render
All the other threads are moved to resolved. This is the only active one. Please refer to this thread only for any updates regarding this.