Search in
Sort by:

Question Status:

Search help

  • Simple searches use one or more words. Separate the words with spaces (cat dog) to search cat,dog or both. Separate the words with plus signs (cat +dog) to search for items that may contain cat but must contain dog.
  • You can further refine your search on the search results page, where you can search by keywords, author, topic. These can be combined with each other. Examples
    • cat dog --matches anything with cat,dog or both
    • cat +dog --searches for cat +dog where dog is a mandatory term
    • cat -dog -- searches for cat excluding any result containing dog
    • [cats] —will restrict your search to results with topic named "cats"
    • [cats] [dogs] —will restrict your search to results with both topics, "cats", and "dogs"

FindFunctionByName() is returning a UFunction* with an invalid Func pointer?

Hey gang! Got a strange issue and we can't seem to pinpoint the cause. Hopefully you have seen/solved this one?

We have a native base class that implements an event OnFoo(). This class is the parent of multiple native subclasses. Multiple blueprint classes have been derived from the native subclasses, and each of them implements OnFoo() within its Graph in precisely the same way. At runtime using a cooked build, when OnFoo() is called, one - and always the same one - of the blueprint classes crashes the game with the nondescript "Fatal error!" message. The crash does not occur in PIE.

Further investigation reveals that when this specific blueprint calls OnFoo(), its class does have "OnFoo" in its FuncMap, but the Func pointer is null. The Engine doesn't currently validate the Func pointer prior to invocation, which causes the crash. (We've since added defensive code inside UClass::FindFunctionByName() to validate Func, and when it fails we continue past, traversing up the Super Class chain until we find a valid match.) Again, this issue seems isolated to only one of the blueprint classes; all the other sibling blueprints contain valid Func pointers inside their FuncMaps.

The question is ultimately, what would cause OnFoo() to be added to this blueprint's FuncMap without a valid Func?

Product Version: UE 4.9
more ▼

asked Sep 22 '15 at 11:01 PM in C++ Programming

avatar image

Brian Fox
6 1 1

(comments are locked)
10|2000 characters needed characters left
Viewable by all users

0 answers: sort voted first
Be the first one to answer this question
toggle preview:

Up to 5 attachments (including images) can be used with a maximum of 5.2 MB each and 5.2 MB total.

Follow this question

Once you sign in you will be able to subscribe for any updates here

Answers to this question