NEED HELP!!!! Sometimes my UE4 doesn't respond to blueprints changes.

Recently I found that sometimes my UE4 “is not responding” to what I tell him to do.
For example, I created this Blueprint in order to spawn 10 floor tiles when the game start.
By the way,I am doing the endless running prototype that is posted on UE4 youtube channel.

After I changed to spawn 10 tiles, (for loop from 0-9), when I hit simulate, it does not show 10 tiles.
Instead of showing 10, it still shows one.
The worst part is when I save all changes and quit the engine, after I open it again, this time it does not show any floor tile at all.
This kind of situation happended to me a few times already.
Is there anyone encountered the same issue? As in sometimes even though you changed the blueprints, the engine does not give you the corresponding respond?

Any suggestion is welcomed!

Thank you.

Be sure to compile the blueprint before running it. Also, it would be worth printing out the transforms location for each of the tiles to make sure they are not being created in the same spot.

In fact, I can see from your screen shots that the transforms are not being updated anywhere in the loop, therefore the ‘Next Spawn Point’ will be the same for each of the tiles meaning that they are actually being spawned but all in the exact same place. You’ll want to update the ‘Next Spawn Point’ variable with the new data within the loop before you actually spawn the floor tile.

Then how to make sure that all the transforms are being updated?
Also sometimes I cannot get the correct result , does it mean that I did not do all the steps in the correct sequence??

Really thank you for the explaining.
I am somewhat a newbie.

In the loop body, before you call your add tile function you could call ‘Set Next Spawn Point’ and provide it with the desired transform data (this must change on each loop iteration). When doing such things I normally multiply the mesh length by (loop index +1) and send the resulting value to one of the location axis (i.e X axis) within the transform.

I see…
I will try to understand and thanks for the help!

You’re welcome and good luck :slight_smile: