FAQ: Are style files backward compatible with previous versions?
Are style files backward compatible with previous versions?
When there are changes made to the persistence of symbol objects during a release, style files created in that version of ArcGIS do not reference in an older version.
It is important to take note that different symbols are used between different versions of ArcGIS; create symbols in the style of the oldest software release version. Styles are forward compatible because the newer versions of the software are capable of consuming older symbols.