Error Function 'XY' called from X Y Using Interface W should not be called from a Blueprint

On editor load there is the following message in the log:

LogBlueprint:Error: [compiler] Error Function ‘SetGameStateMission’ called from Set Game State Mission Using Interface GameState_Interface_C should not be called from a Blueprint
.
LogBlueprint:Warning: [compiler] Warning [0006.58] Compile of MissionBase failed. 1 Fatal Issue(s) 0 Warning(s) [in 30 ms]

The function takes a Mission type input and assigns it to a variable so nothing fancy is going on. That function is called from many other classes and those compile fine. Other functions through the same interface is called in this failed MissionBase class, earlier in the event chain, and they are apparently all ok too.

If I make a new function with a different name like “SetGameStateMission2” with the same definition and use that then no error. Even more weirdly if I start using “SetGameStateMission” again instantly then it’s fine too. However after deleting “SetGameStateMission2” from the interface and its implementation (while still calling the original, magically fixed function) the error comes back.

The game actually loads and functions properly in PIE and when packaged up. Standalone crashes because of this problem. Interestingly one of the functions showing up in that crash log is the one mentioned here.

I tried to repro it in an empty project but couldn’t but I could send you the whole project via email.

Branch: Binary
Build version: 4.4.0-2255576

Hi ZoltanE,

If you could, please Private Message me a link on the forums to download your project. Using Dropbox or Googledrive is perferred.

Thanks, TJ

I see exactly what you are talking about. I have roped in another developer and we’ll post back here as soon as possible.

Hi ZoltanE,

I’m sorry it’s taken a few days to get back with you. I just wanted to let you know that I have submitted this issue as TTP# 345370 into our tracking software and one of our developers will be looking into the issue. We will post here as soon as we have something for you.

Thanks, TJ

Great news, thank you.

We are blocked by this same issue, hoping for a speedy fix!

A lot of people have same issue. I think problem in libraries loading sequence. Developers, please let us know when you will investigate the problem.

Thank you.

Hey everyone,

I just wanted to let you know that I updated the TTP to let the devs know that multiple users are seeing this issue. We’ll post back as soon as we can.

Now I’m at a point where any meaningful changes crashes the project on the next startup, with the aforementioned sort of errors. Otherwise, when everything loads, there are no such errors in the log. There is no indication while editing that the project won’t load anymore, everything compiles and runs in PIE fine.

If it helps I can send you the project with two of the BP asset files in two versions: one old but safe and one where editing was done and now causes a startup crash.

Hi ZoltanE,

Our devs are still investigating the issue. If you would like please feel free to PM me the links to download the other projects and I will attach them to the TTP.

The issue is still here in 4.5.0-2326478, even after migrating everything to an empty project. The critical step in my case seems to be casting the return value of GetPlayerPawn() to my custom pawn class or any of its children. (Even if I just place the node and don’t actually use what it returns.) Casting to other pawn types works fine.

Now I’m restarting the editor after every single blueprint edit and I found another particular condition triggering the startup crash: if my gamestate interface has a function with an input or output type of DroneBase, a pawn derivative class. Having a Pawn type there instead is fine. Any ideas what to look/test for in the custom pawn blueprint?

Hi ZoltanE,

For reference, we recently moved to a new tracking software and this issue is now logged as JIRA UE-3752. Our developers are still looking into what could be the cause of the issue.

I’m going to bump this thread, because we ran into what I believe is this exact issue whilst doing the December UE4 Game Jam - it prevented our submission from being playable. It’s a pretty serious issue because it’s affecting multiple actors across our game and it prevents us from releasing a playable version to the public like we intend to this week.

I believe it is the same issue also mentioned in this thread:

Our game works perfectly fine from within the editor, but when trying to run a packaged / standalone version of the game the blueprints stop working. In our case, we have actors that are calling functions in other actors - in some cases instances of the same type of actor, in other cases different types actor, and in a few cases this causes the above error message.

Thanks!

We’re seeing this in the launcher 4.6 version.

Thanks!

Hi ambershee,

I updated JIRA UE-3752 with your info. What version of the editor are you seeing this error in?

I understand that there is no fix yet for this issue but can you give some guidance how to avoid or work around the issue?

I’m in an increasingly difficult position, where I’m ready to throw out everything related to my pawn and start over from scratch. However I’d like to make sure then I won’t end up with the same issue again at the end. Any additional info would be appreciated and perhaps used by other members to get to the bottom of this.

Are you using event dispatchers perchance? We removed a load from our game jam game and it may well be what caused our issue.

No, I’ve never used them.