I'm the developer Nyx Voltron, a live link between 3ds Max and AE, and I've encountered a bug in the latest 2015.3 AE version that didn't exist in earlier versions. I'll file a bug report as well but maybe someone here knows a solution..
Somehow I end up with cameras, that are created by JS, that slowdown AE when they overlap on the timeline, Before/after the overlap there is no problem,in between AE doesn't crash but it slows to a crawl with UI interaction delays that take up to a minute or so. As said, the non overlapping parts of the timeline work as normal so I guess it isn't some camera setting that is out of whack.
The AEP file that has the problem can be downloaded here, Dropbox - cam_bug.zip if someone can confirm it has the same issue on another system that would be great, only happens since update to 2015.3 as far as I can tell.