Since fixing JCR-1272 the exception thrown when attempting to restore certain properties have changed. This issue was fixed in JR 1.4, hence any version of Magnolia using JR 1.4 or higher is affected.
The change was necessary to tackle the concurrency issues in JR, but broke the exception handling in CopyUtils while attempting to restore the properties. When versioning nodes, it is possible that subnodes versioned together with the parent end up with jcr:isCheckedOut property with (or without) value. While prior to JR 1.4 attempt to restore such property ended up with ConstrainViolationException which is silently ignored by CopyUtil, now this doesn't work any longer as the RepositoryException is thrown when property with no value is found.