Studio crashes if an effect has been manually removed from effects folder

Having an effect in the timeline which is missing from the effects folder will crash the editor when attempting to save project. The effect needs to be manually removed from the folder. 

How to reproduce.

Add an effect.
Add the effect to timeline.
Remove the effect from the effects folder via file explorer.
Re-open presentation
Edit something and save

The effect still needs to be in the timeline after being removed from the effects folder.