Spline reset error (how to replace a blueprint with a backup copy?)

I have a blueprint with an object moving along a spline that i designed with a lot of precision. Now, there is a known bug that resets the spline to only 2 points when compiling the blueprint with an error (Spline points randomly reset - UE4 AnswerHub), and that’s what happened to me. To create a new spline is not an alternative.

I do have a backup copy of the whole project, with the blueprint (and spline) intact. The problem is that it doesn’t work to just copy that working blueprint to the project, bcs the spline seems to be somehow in the level and not within the blueprint, since it is always edited in the level and not in the blueprint.

I have a deadline coming up really soon and this is the worst possible situation, any help would be greatly appreciated!

Thank you very much

When i copy the blueprint from the backup, the spline comes with only 2 points, no spline point coordinates seem to be stored in the actual blueprint, but in the level.