If I get you right, you can’t reply…
It’s just an information, the the user didn’t know how to solve your report.
Too bad he closed it like that. But perfect you came here. Welcome to the forum 
You can contact the user via private message.
Or edit the map by yourself.
Check your local wiki (www.waze.com/wiki) and read the forum.
Have fun 
- You should have a message in your app inbox and you can reply from that message.
- The link in the email takes you to the map. If you log in with your Waze credentials, you should be able to click on the map error (Update Request) that you submitted and add your message.
If those don’t work, as noted above, you can use the forum Private Message (PM) functionality and address it to the username you received in the email.
Your description sounds like an issue where the GPS location of that address is closer to the dead end road than to the main road. This can be fixed on the third party site by moving the address pin closer to the main road and the editor probably should have looked into doing that before closing the report (and making sure the internal address is set correctly at the same time). Once Waze’s internal addressing is finished and working, we won’t need to worry about third party data being wrong and can fix it directly in Waze.
If the problem is with the third party location and you want to tackle that yourself, you can fix it through Google’s map editor. If it’s a time where Waze’s internal addressing is being used, you can fix it in Waze’s editor yourself if you want. Just be sure to read the editing Wiki pages first. If you’d prefer not to try fixing it yourself, you can post it in the Virginia forum with a permalink and someone there will likely fix it or you can submit a map error report with details explaining the problem and someone can fix it that way as well.
Check out Item #28 of the Waze FAQ for info about why Waze is routing you around the block.