features fail in 2014 that were fine in 2013

Some part features that regenerated in SW2013 fail when opened in 2014 and 2016.  One part is fine in 2013 and 2016, but fails a feature in 2014.  Is SW not fully upward compatible?

Examples of (4 different parts) features that fail when opening 2013 parts in 2014 & 2016.

1.  A cut to surface fails due to a surface extend produces different results in 2014 than in 2013.

2. A round fails to regen in 2014, but works in 2013 and 2016

3. A mirror body fails to regen in 2014 & 2016.  However, If I create a new mirror exactly as the failed mirror, in 2014 & 2016, it works.

4. A circular pattern fails to regen in 2014 & 2016

SolidworksParts And Features