Orient to path problem

I have made five identical (except for the size) animations in Animate CC where I want an object to "Orient to path". It works fine in Animate CC, but when I export the oam it doesn't work as it should. Three out of five work fine, but two does not orient to path. Also – when I export the files from Animate CC a warning about this problem pops up. How to solve this? Why is some fine and some not?

Thanks in advance.