Waze uses a third party forum software called phpBB to run its forums on.
This software has a feature that attempts to keep large searches from slowing down the forums for everyone. Unfortunately this feature causes words that are commonly used to not be searchable.
A workaround for this is to use Google's site specific search to look for posts.
In Google search for:
SITE:WWW.WAZE.COM/FORUM <your search term(s) here>
eg: no permissions
SITE:WWW.WAZE.COM/FORUM "no permissions"
Note that this workaround has a limitation that Google would have to have indexed the topics being searched. So newer topics may not be available at the time of your search.