Noticed it during JENKINS-37545.

Reproduction steps:
1) Manually deploy a plugin with detached dependencies and permission groups (e.g. Ownership 0.5)
2) The loading should fail...
3) Install missing dependencies
4) Deploy the plugin again
5) Change the log

Expected behavior:
The plugin installation succeeds

Actual behavior:
Plugin installation fails due to the missing permission group

Workaround:
Restart the instance