After fixing the crash from [Link Removed] when compiling the child blueprint that has claimed the component name the parent was previously using without having compiled the parent, an internal compile error will be reported.
Compiling the parent and then compiling the child works just fine.
In general, it seems correct that if a parent has been structurally modified, any attempt to compile a child blueprint should recompile the parent first.
Steps: Start a new blank BP project.
Note the compile error Internal Compiler Error: Tried to create a property Crash in scope Beta_C, but another object (ObjectProperty /Game/Alpha.Alpha_C:Crash) already exists there.
There's no existing public thread on this issue, so head over to AnswerHub just mention UE-82858 in the post.