No problem about the log, your steps to reproduce it are quite reliable and I see the error message (apparently something about this action breaks the undo history).
This is... really weird! And there are tons of RP users, not to mention I've been using it for ages, but never anything like this. However, a quick test shows that copy-pasting any single cell on any layer but the first
always reproduces this error, so it should be easy to fix.
This isn't anything with your particular file (I tried it on others, and as expected got the same results).
Perhaps part of why this hasn't been discovered: Remember that you can copy-paste a single cell more efficiently by right-clicking on the origin and left-clicking on the destination.
Okay so copy pasting (and honestly, sometimes, trying to draw) is pretty flaky in this file o.o
Let me know if you find any other actions that produce strange results. This looks like an isolated incident related to this particular series of actions, and there's nothing wrong with your XP file itself.
Thanks for the report, I'll make sure this is fixed for the next release.
Edit: This has been fixed in the 1.0 release.