If a function inside a BlueprintFunctionLibrary class is declared as static, instances of the function node inside blueprints cause the blueprint to not save after a hot reload. This does not affect static functions in other classes that can still be saved.
From the ticket, the nodes are ending up pointing at the junk old CDO. It changes
ActorBP is unable to save
Blueprint saves successfully after hot reload.
Head over to the existing Questions & Answers thread and let us know what's up.