did you modify in any way the file: /var/lib/openhab2/etc/users.properties ?
if yes: make sure that you have the ,_g_:admingroup part at the end of the user line and the last line is: _g_\:admingroup = group,admin,manager,viewer,systembundles
openhab> help bundle:
COMMANDS
bundle:capabilities Displays OSGi capabilities of a given bundles.
bundle:classes Displays a list of classes/resources contained in the bundle
bundle:diag Displays diagnostic information why a bundle is not Active
bundle:dynamic-import Enables/disables dynamic-import for a given bundle.
bundle:find-class Locates a specified class in any deployed bundle
bundle:headers Displays OSGi headers of a given bundles.
bundle:id Gets the bundle ID.
bundle:info Displays detailed information of a given bundles.
bundle:list Lists all installed bundles.
bundle:load-test Load test bundle lifecycle
bundle:requirements Displays OSGi requirements of a given bundles.
bundle:resolve Resolve bundles.
bundle:services Lists OSGi services per Bundle
bundle:start-level Gets or sets the start level of a bundle.
bundle:status Get the bundle current status
bundle:tree-show Shows the tree of bundles based on the wiring information.
If i am trying the start command i get this Feedback:
openhab> bundle:start 215
Command not found: bundle:start
e.g the bundle:list command works, so i assume that this could be a user rights Problem.