Blueprint Node disconnects after editor restart, claiming Pins are a mismatch

I did run into a Problem now, where the Pins from a Structure keep disconnecting after i restart the editor. It worked fine so far for several version of Unreal, inkl. 4.25 until a few days.
The editor will always say, the Pin is a mismatch until i refresh the reserving node. Then I can connect them again and everything works fine in game.

I tried to make as copy of the UI Blueprint that has the problem and see if it fixes this. No luck there, still same problem.
I also made sure to save all several times and even save the Blueprint directly - also no luck.

Did you try re-making the nodes? ( the accepting ones )

Well, if I copy the Blueprint that accepts the Pins, it actually does work again. But this isn’t a solution at all. Because the automatic replacement of references doesn’t seem to work (when I delete the broken one).
And replacing it everywhere manual + fixing all the other Pins that are breaking after that…

Also this doesn’t go to the root of the problem. Since it works till the editor is closed, so why won’t it work after opening it again?
I really don’t want to have to do this over and over again (especially once the game gets more and more complex).

I have seen this a number of time ( in posts ). I do have a vague recollection that somebody solved it ( sorry it’s vague ). I do recall they looked at the C++ code for the node and there was a typing problem - I think…

Is it a node that starts off with wildcard pins? ( What nodes are concerned? )

I am not very familiar with C++.

Well its basically just an UMG Blueprint I use in another (to show the Items in an Inventory). So it gets several inputs. All stay connected except the one with the Structure for Slot Content.

It also usually breaks, when I change something in the Structure (through that is understandable). This time it broke for no reason (I made a new map) and this time it won’t stay connected either.

Right. Tiny light at the end of the tunnel.

What I -think- is going on is that there is a connection / node definition that has not propogated through the system cleanly.

You need to look at the offending BP in the reference viewer and see all other assets it depends on. Open the most distant BP it depends on, refresh all nodes and recompile.

The work you way back towards your main BP using the same procedure. Finally refresh and recompile in your main BP.

Does that make sense?

Thank you for your help. Guess I’ll have to redo some code and make everything more modular, so changes wont affect as much anymore.
Maybe this will help in the future.

I don’t think there’s anything wrong with your code, it’s just that a type setting hasn’t been propagated fully between a series of blueprints…

Yea, but my thinking is: More Modular → The amount of damage something like this can do, will be smaller. So future fixing stuff, will be less of a pain :slight_smile:

Ok, if you want to get more modular, start getting into:

  1. BP interfaces ( the crucial thing about BPI is that when you make the call, you do it on an ‘actor’, you don’t need to know the type of thing you’re talking to ).

  2. Event dispatchers

  3. Possible also look at something like:

That is a very helpfull advice. I will look into the marketplace thing as well. Also I am always a bit skeptical about such addons / plugins. Because once I depend on it and for some reasons, there aren’t any more updates, I couldn’t use newer versions of the engine anymore.

Yes, there is that. It’s a good idea to use ones that have been around for many versions and have a good star rating. Then you’re probably ok…

It is possible to do global event processing using the game instance. Not quite a slick as a plugin, but possible…