Blueprint breakpoint is never hit


I’m trying to understand the way the BP_DemoRoom works. I got it from here:…ntent/DemoRoom

I tried to debug it in both an empty Blueprint project or an empty C++ project, both created without starter kit assets, where I copied the DemoRoom directory in the project’s Content directory.
In the editor (UE 4.22.1) it’s just enough to drag and drop its BP_DemoRoom blueprint from the Content View to the Viewport and it works as expected.
I can also edit it normally in its BP editor.

The problem is, in whichever of the two projects above, when I add a blueprint breakpoint to whatever of its nodes, it shows as a valid (red) breakpoint on the node itself and in the debug window but then, with “BP_DemoRoom” selected in the debug filter, if I play the game (doesn’t matter if in the main editor or in its BP editor) the breakpoint is never hit.

I also compiled and saved the BP_DemoRoom BP before playing the game.

What can be wrong?



thanks for replying.
I just started to learn BP. The breakpoints are right in the construction script.
I read on SO that the BP to debug had to be selected in the debug filter in order for the breakpoints to work.
So is there not a way to debug the construction script?
The whole BP is quite big and with many sub functions called by the construction script.

Thanks very much for your comprehensive explanation and links.
I had previously studied the official debugging documentation but that didn’t say much about this kind of details.
On the contrary your answers (in the other link too) are much more helpful.

So, if I understand correctly there’s no way to use the debugger in PIE and SIE for a constructions script -CS-since the object already exists and CS already ran before there was a chance to debug it. I made a couple of experiments more and they seem to confirm it.

Aside for “print string” and similar other methods you suggested in your other forum’s reply, to your knowledge, would there be any other way to execute that BP script (in all its entirety: with all its sub-functions) having a chance to debug it with all debug features on? (i.e. to spawn the BP_DemoRoom on demand).
In other words, can a BP CS context ever be debugged in the editor debugger (as a result of an event, for example, or even moving out that very same code from the CS itself) or there’s something that prevents that in any circumstances?


Thank you very much for all your help and precious insights.
I’m gonna try these options and see if I can debug through it.