Server error status: OK [200] when trying to install new WPMUDEV plugins.

Server error status: OK [200] when trying to install new WPMUDEV plugins.

I recently changed the primary domain on this WPMU installation... since changing, i removed and re-added the site to the WMPUDEV dashboard , regenerated the API etc.

I still get an error when trying to install through the WPMUDEV manager plugin - and on the wpmudev website it fails also (telling me to install the latest version on wpmudev manager - which i had already done, reinstalled etc)