I am running version 1808360 (64-bit) inside a Debug build in MS Visual Studio Pro 2012.
While running a customized version of the “Top Down” project, I consistently get a crash when I select the “Lit” button in the main editing viewport and then mouse down over “Visualize Buffer.” It tells me that Rocket has hit a breakpoint, even though I do not have any breakpoints set in my code.
I’ve attached the call stack I get in Visual Studio, even though it’s not particularly useful.

Hi Paul,
This is a known issue and actually has nothing to do with you being in Debug or a customized project. Simply bringing the mouse over Visualize Buffer will cause the crash. This issue is already fixed for the next Beta release.
In the meantime, you can view the forum post about this that provides a workaround:
http://forums.epicgames.com/threads/973020-Beta-4-Visualize-Buffer-crash-workaround
Cheers
This is a known issue and Epic is aware of it. Fortunately you can find a workaround posted by Athos Sampaio below.
https://rocket.unrealengine.com/questions/4752/bug-hovering-over-visualize-buffer-crashes-the-edi.html