It has come to our attention that one or two Vensim users have continued to receive this error, although it is quite rare. It occurs when trying to save a model. Vensim thinks there is a special sketch object in the form of a bitmap or metafile but could not find the object. It seems to result from combinations of paste, delete and undo.
If you do get this error, closing and reopening the model should fix it, as should a reform/clean.
We will, of course, endeavour to fix this.
Lee