Steps to reproduce:
1. add a sprite
2. associate an effect to the sprite
3. create a family
4. use the effect of the sprite inside the code (for example enable it)
5. into the code, convert the sprite into the family
If you try to replace a sprite with a family/sprite that doesn't have the same behaviors or variable, it thrown an error. But if you follow the steps, the part of code you have tried to convert will be deleted.
It should send a warning that there are no object with the same effect, like it does with behaviors and variables.
Construct 2 version: