Hey! Hope you're doing well.
So, I finally got around to testing GWT Navigator—you know, that tool for debugging GWT applications we talked about. I've been wrestling with a legacy app at work, and the browser dev tools just weren't giving me enough visibility into the client-side RPC calls.
Install was smooth—standard macOS app bundle. Launched it, pointed it at my local dev server, and… nothing. The app window opened, but it just showed "Waiting for connection" indefinitely. No errors, no logs, just spinning.
The Wrong Turn
First thought: maybe it's a port issue. Checked my dev server—definitely running on 8080. Tried different URLs, even the example ones from their docs. Same result. Spent 30 minutes convinced it was a config problem. I even reinstalled it twice, thinking maybe the download was corrupt.
The "Aha!"
Then I remembered: macOS has gotten really strict about Local Network permissions for apps that need to inspect traffic. Even though GWT Navigator connects to localhost, it still needs permission to monitor network activity. Went to System Settings > Privacy & Security > Local Network, scrolled through the list… and GWT Navigator wasn't even there. That was the clue—the app had never requested permission, so macOS was silently blocking it.
The fix was a bit hidden: I had to completely quit the app, then hold down the Option key and right-click the app in the Applications folder, select "Open" from the menu, and click through the security warning. This forces the app to re-register its permission requests with the system. After doing that, GWT Navigator appeared in the Local Network list with the toggle off. Flicked it on, restarted the app normally, and it connected instantly.
I found this page with the system requirements that actually mentioned a similar issue in the user comments—super helpful for understanding the pattern: the resource I used.
Quick Fix
If GWT Navigator won't connect:
- Fully quit the app
- Hold Option, right-click the app in Applications, select "Open"
- Click through the security dialog
- Go to System Settings > Privacy & Security > Local Network
- Find GWT Navigator and enable the toggle
- Restart the app normally—should work now
Apple's Local Network privacy guide explains why this happens. For GWT debugging once you're connected, the official GWT docs have great tips.
Anyway, it's working perfectly now—being able to inspect RPC payloads directly is a game changer. Let me know if you try it!
Talk soon
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