When porting the GeoServer plugin for GeoGig from Boundless repos to the GeoServer community module, I missed 1 dependency in the assembly XML for the plugin that is needed for Open Street Map capabilities. I created a JIRA for this here:
https://osgeo-org.atlassian.net/browse/GEOS-7439
The one line fix is in a PR here:
https://github.com/geoserver/geoserver/pull/1518
NOTE: The GeoGig community plugin is currently only in the 2.8.x branch (not in master yet, no plans to back-port it to earlier versions of GeoServer).
Many thanks,