The documents produced by WordsProcessing and SpreadProcessing are compliant with the specification. But, Open Office, Numbers and Pages (the default applications for working with .docx and .xlsx on MAC) are unable to open documents where the target attribute of the relationships of the documents is specified as an URI, instead of as a relative reference. According to the specification (Ecma Office Open XML Part 2 - Open Packaging Conventions) both formats are acceptable. The issue is in the relationships parts, relationship element. The Target attribute can be either a URI (Target="/word/theme/theme1.xml") or a relative reference (Target="theme/theme1.xml") as stated in the specification. The document processing libraries use URI, which OpenOffice is unable to interpret, despite them being allowed by the specification. The fix will be available in our official release Q2 2016.