If you want to get the parent bone name of a bone with "ent_boneparent", it crashes if you give "1" as bone index (bone 1 has no parent). The strange thing is, it only crashes in RELEASE mode, not in development mode. Not even a warning with warn_level=6.
Please find attached my testlevel. First test it in development mode, everything should work. Then publish it, and test it again, it should crash now.