This may not be new but it was to me.

I did the 4 gb patch and unchecked the undo's in SE. In xlights I only had one Model of 32 universes with 300 channels each. I discovered that a 346mb lcb clipboard would not paste into my lms file but a 356mb lms file painted into it. The SE memory (Task Manager) went to 3.6 gig doing the paint. It stopped at 820mb with the lcb paste and did nothing. This was tried on 2 machines, Windows 8.0 and 8.1, lots of power.