[4.6.1] Invalid class with which to make a Blueprint

Development Programming & Scripting Blueprint
, , , ,
1

I saw in another post where this was an issue in 4.1, I am still seeing it as an issue in 4.6.1. I created a Blueprint Object that inherits from Object, but I am not able to create a child blueprint based on it. When I try, I get message:

Invalid class with which to make a Blueprint.

2

Hi RAVaught,

Thanks! This is a known issue that has still not been resolved. I have pulled up report (UE-3952) and added notes that this still occurs in 4.6.1, and I’ll let you know when I see an update on it.

3

Thanks . This is another one of those issues that should DEFINITELY be in Documentation. Heck, could we get like a single page per answer section on here that just has a lists of known major issues like that? Would be a great place to get user input on bug/feature priority for community too! I know you guys have your roadmap, but we have limited feedback on that. I found out after I posted question that it was an old issue, since 4.4, but could not for life of me figure out why there was no mention of this problem in documentation.

On another note related to this ticket:

Are you aware that you can’t re-parent an object to an actor type, which means if you make mistake of writing a bunch of code on an object only to find out you can’t instantiate it, you can’t convert it to a new type to save your work either? Is there any plan for some kind of conversion tool? Also, do you know if UObject upgrades coming in 4.7 that were mentioned in release notes fix any of these issues?

4

We’re exploring a few different options to make bug report status and known issues more accessible, and that is being considered. Feedback is definitely part of plan.

I know that you can’t re-parent between types like that, but I can go ahead and enter a feature request for it. It’s likely not to be implemented, however, because of potential problems that will arise when trying to automatically convert an Actor to an Object or vice versa, or any other class.

Unfortunately only information we have about upgrades coming is same that you have, “UObject usability improvements.” I’ll see if I can find some more information on that for you.

5

Thanks for updates . In absence of being able to re-parent between types, maybe a way to migrate functions/dependencies between objects that don’t rely on feature specific elements of a class. For example, in my object, I had a few variables based on structs, and all of my functions were based around using those variables to do certain things. There was nothing in them that would have required anything overly crazy or specific to an object or actor. Being able to migrate those would be darn useful even if it would fail to migrate functions that didn’t meet some criteria of isolation.

6

Hey ,

inability to create a child of an Object Blueprint has been fixed internally, and should appear in 4.8. CL for fix is 2398267, if you want to grab it from GitHub.

There is another bug involved in which Object BP won’t appear as an option in Create > Blueprint search options, but right-clicking it in Content Browser and selecting ‘Create a Blueprint based on this’ will create a child BP. I entered a new bug for that in UE-7179.