Is there a way to do a batch import of extensions? I have an offline installation and I would like to set up a mirror of the xwiki extension server to point to.

I cannot get the Extension Mangers to install properly (nor can I find a proper location to ask for help. I simply get this message, with no further details in the logs:

Importing org.xwiki.platform-xwiki-platform-extension-ui-9.4.xar: Error while importing
•1 Page(s) installed
•0 Page(s) skipped
•2 Page(s) with error

List of installed pages
•XWiki.ExtensionHistory

List of erroneous pages
•XWiki/Extensions.xml
•XWiki/ExtensionUpdater.xml

How do I correct this?