Here was a validation query we came up with during the issue investigation that should help anyone else see if they are having something similar in their v13.x systems before they upgrade:
select code, view_type, principal_type, principal_id, view_subtype, object_code, partition_code, count(*)
from odf_views
group by code, view_type, principal_type, principal_id, view_subtype, object_code, partition_code
having count(*) > 1
The idea behind this query is that we would only expect a single view with a given name (code) and those other columns per partition code value (so if the object was partitioned, it wouldn't be abnormal to see more than one projectCreate_default view for example, but if it shows up in the query above where those other columns are also identical, then we almost certainly have a problem that support can inspect further and confirm or help remedy).
It was, in this case, also resulting in this error message in the logs (I've anonym-ized the content a little):
FATAL 2015-08-24 12:11:51,924 [http-bio-80-exec-28] web.VXSLServer (clarity:anonymous:XXXXXXX__XXXXXXX-XXXXXXXX-XXXXXXXXXX-XXXXX:odf.objectPropertiesFields) Transformation fatal error:Error in call to extension function {public static java.lang.String com.niku.union.xsl.NumberExt.formatPercent(java.lang.String,java.lang.String,int)}: Sequence contains more than one value; Java method expects only one; SystemID: file:/C:/ppm14204/META-INF/odf/vxsl/view/commonTemplates.xsl; Line#: 1048575; Column#: -1
; SystemID: file:/C:/ppm14204/META-INF/odf/vxsl/view/commonTemplates.xsl; Line#: 1048575; Column#: -1
net.sf.saxon.trans.DynamicError: Error in call to extension function {public static java.lang.String com.niku.union.xsl.NumberExt.formatPercent(java.lang.String,java.lang.String,int)}: Sequence contains more than one value; Java method expects only one
However, it can be possible that different views would produce different errors - it really just depended upon the attribute type it tripped over first, and it could easily vary in other systems/configurations.