Issue first appeared in https://ci.appveyor.com/project/drewwills/uportal/build/1.0.869 after https://github.com/Jasig/uPortal/pull/1048 was merged.
Curiously the build before the merged passed https://ci.appveyor.com/project/drewwills/uportal/build/1.0.867
and #1048 does not include any code or test changes, so I suspect is may be a AppVeyor environment change that triggered the error, possibly a new Java version.
Confirmed, XSD error does not happen on previous AppVeyor environment (Java 1.8.144) https://ci.appveyor.com/project/ChristianMurphy/uportal/build/1.0.13
shows up for Java 1.8144 but not for Java 1.8.152.
Issue impacts 32bit and 64bit Windows Java 1.8.152 versions.