I created a model that worked fine in QGIS 2.14. With help I included a script in the model that prevented the model from running unless a feature was selected. But after upgrading to 2.18 the model no longer runs unless I remove the script.
The above does exactly what I want it to do in 2.14 so I don't understand why it won't in 2.18. I have a couple of other models that use the same script for the same purpose and have the same issue. I have tried this on my PC at home and on my work PCs and still have the same issue.