[Bug] Exception when loading frames after a recording

[NickeManarin]

Some users are experiencing an exception when finishing a recording and loading the frames inside the editor.

► Title - 
	Error in loading frames
▬ Message - 
	Collection was modified; enumeration operation may not execute.
○ Type - 
	System.InvalidOperationException
▲ Source - 
	mscorlib
▼ TargetSite - 
	Void ThrowInvalidOperationException(System.ExceptionResource)
♠ StackTrace - 
   at System.ThrowHelper.ThrowInvalidOperationException(ExceptionResource resource)
   at System.Collections.Generic.List`1.Enumerator.MoveNextRare()
   at ScreenToGif.Windows.Editor.Load()