Hi Marco,
Let me start by saying based on the information presented here, I don't believe this to be directly related to scripting. The ClassCastException makes sense if the embeddings mapping appeared to be a float type to the script.
Now, it's certainly odd that embeddings appeared as a float type, though. Are you able to reproduce this issue? And if so, would you please provide the steps you are taking to do so? Also when you say "reloading data" what do you mean by that?
Thanks!