'No Debug Data' info on variables during debug phase (breakpoint)

Development Programming & Scripting
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During testing phase in unreal blueprints, we noticed that there are several points in Unreal Blueprints debugging where we cannot see Data from variables during debug phase (breakpoint). This is most visible in ForEach where we cannot debug what is present in ArrayElement variable if we put breakpoint into LoopBody. No Data reading can also occur if we try to read element at specific index from array and break it into individual variables from struct. At that case, values on Break node will also tell No Data.

Toggle “Watch this Value” didnt help with our problem.

Is there any way to set data always visible or is this by design? And if so, is it possible to find out whether the option of always visible data can be “somehow easily” added?

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Steps to Reproduce

  1. Create array struct variable in blueprint (use Box struct for example)
  2. Pass this array into ForEachLoop
  3. Break ArrayElement from this ForEach.
  4. Put any type of code that will request reading from variable in Break node (for example in Box struct, check if box is valid with Branch node) in LoopBody.
  5. Put breakpoint after this reading
  6. Run game mode
  7. Observe how ArrayElement or any variable from Break node will tell ‘No Debug Data’
3

Hi,

Thank you for the detailed repro steps! I managed to recreate what you’re seeing and passed a question to Epic to see if it’s bug or limitation of the Engine.

If it is a bug I’ll go ahead and update this post with a public issue tracker link.

That being said as a workaround, you could promote the pin you wish to watch to a variable.

Once you have that variable, in the loop body set that variable to the pin. That variable will be updated in the blueprint debugger which you can always have visible as shown in the following image:

[Image Removed]Thank you for your patience!

Edit: I went ahead and escalated it, apologies for the delay

Regards

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Hey there, the blueprint debugger hasn’t received much attention in a while. I’ve talked to the system owner and they confirm that these are bugs. I’ve enter this into our issue tracker as UE-315391. We’d like to add support for inspecting those output pins at some point, but realistically the bug won’t be treated with high priority. In the meantime I would also recommend John’s workaround of introducing member variables or local variables since those can reliably be inspected.

We appreciate the bug reports!

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Images aren’t publicly visible on the issue tracker but this is the annotated screenshot I attached to the bug so that the system owner knows which pins to work on.

[Image Removed]

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Closing this but feel free to keep responding, which will reopen this case.