Hi,
It appears the EXPath package format has changed. The current version of the spec reads:
the root of the ZIP file contains a directory named *content*, containing the components and any other file the package needs.
http://expath.org/spec/pkg#descriptor
A previous version http://expath.org/spec/pkg/20100107#d2e112 reads
Alongside this descriptor, the root of the ZIP file contains a directory *named after the module name* (see below) which contains the components and any other file the package needs.
BaseX appears only to support this earlier version. If a package using a *content* folder is installed the following error is reported:
[bxerr:BXRE0004] Package descriptor: Invalid attribute 'name'
/Andy