org.xwiki.wiki.manager.WikiManagerException: wiki id is not valid

this error.png appears if:
A) Double clicking on 'Create' button in Step 2 of the Wiki creation wizard, see step2.png

B) Clicking on create -> viewing the Distribution Wizard -> hitting 'back' from the browser -> clicking on create again.

The wikis are getting created, so the error actually refers that the 'wiki id is duplicated' or that the 'wiki already exists'. The error that the 'wiki is not valid' is not necessarily correct, since the id is actually valid.

Not sure how you will mark this issue (might get closed as Won't fix), but the problems I want to highlight with this issue:

• because right now when you create a new wiki you get the DW (actually XWIKI-9456 is not yet fixed on 5.3M2) users might believe that the creation will be finished after the DW completes, not just after hitting the 'create' button;
• the error message could be improved to state the 'duplication' not the 'invalidity';
• maybe some safeback in case of double clicking?

Let me know what you think. Thanks