Wiki Is Empty After Installation
Explanation
XWiki is installed and starts, but its Home page does not exist and the wiki has no application, no panel and no menu. The Distribution Wizard does not open either, so there is no obvious way to fill the wiki.

Cause
An installation holds no wiki Page of its own: the Pages come from a flavor that the Distribution Wizard installs on the first visit. The wiki is therefore empty whenever that run did not finish, and which answer ended it decides whether the wizard ever comes back:

- "Never" records that the wizard must not run again on this wiki, for every step it had left. The record outlives a restart, so the wizard does not come back on its own.
- "Later" records nothing, so the wizard asks again after XWiki is restarted.
- Closing the browser answers neither, and the wizard asks again on the next visit.
Solution
Delete that record so the wizard runs again, the way Distribution Wizard Does Not Appear at Startup describes, then install the flavor.
FAQ
Is the content of the wiki lost?
No. A wiki that was never filled has nothing to lose, and deleting the wizard's record touches no wiki Page: it only makes the wizard ask again.
Why is the wiki still empty after the wizard ran?
The flavor was not installed, usually because the instance could not reach the extension repositories. See Install XWiki without Internet Connection.
Can a wiki be emptied on purpose to start over?
Yes, that is Rerun the Distribution Wizard on an Empty Instance, which drops the database and the permanent directory.