This isn't a big report but a help guide (idk where else to put this) #391
Description
Device Type
Windows
Dev Manager Version
Doesn't matter I think
Model
Blank since this is a help
webOS Version
Blank since this is a help
Rooted
No (with Dev Mode)
Bug Description
Ultimate Guide: Fixing webOS Dev Manager “Failed to get SSH private key”
(LG webOS TV + Windows, safe for public sharing)
This guide fixes the common situation where webOS Dev Manager suddenly stops working, shows SSH/key errors, or refuses to connect even though it worked before.
What you need (ABSOLUTELY EVERYTHING)
Hardware
LG webOS TV (Dev Mode supported)
A Windows PC (Windows 10/11)
Ethernet cable (strongly recommended)
Wi‑Fi can work, but many routers block device‑to‑device traffic
Software / Tools
You must have all of these:
LG Developer Mode app (installed on the TV)
Node.js (LTS version)
Download from: https://nodejs.org
Required for CLI tools
webOS CLI tools
Installed via Node.js:
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npm install -g @webos-tools/cli
webOS Dev Manager (any version you prefer)
Windows Terminal / Command Prompt
File Explorer
A web browser
Windows Defender Firewall access (to allow/block if needed)
Important background (WHY this breaks)
This error usually happens because:
Old SSH keys are left behind
Previous Dev Manager versions generated corrupted keys
Wi‑Fi routers block local device discovery
Firewall silently blocks the CLI
Old emulator keys interfere with real TV keys
The fix is NOT one command — it’s a full reset of the local webOS SSH setup.
STEP 1: Prepare the TV (Developer Mode)
Open Developer Mode app on the TV
Log in with an LG developer account
Yes, LG’s site is bad
Yes, you must make an account
Enable Developer Mode
Enable Key Server
Note:
TV IP address → <TV_IP>
Passphrase →
Make sure the session timer shows a large value (e.g. 999h)
STEP 2: Use Ethernet (VERY IMPORTANT)
Connect:
TV → Router (Ethernet)
PC → Router (Ethernet)
You do not need two cables if only one device supports Ethernet, but both wired is best.
Why:
Many routers block Wi‑Fi device‑to‑device traffic
Ethernet bypasses isolation issues completely
STEP 3: Verify network connection
On Windows, open Command Prompt:
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ipconfig
You should see:
IPv4 address like 192.168.x.x
Default gateway like 192.168.x.1
Then test:
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ping <TV_IP>
Expected result:
Replies with low ms (1–5ms)
Occasional timeout is OK
No constant “Destination host unreachable”
If ping fails → network issue, not a webOS issue.
STEP 4: COMPLETELY RESET SSH KEYS (CRITICAL)
This is the step most guides miss.
Open File Explorer
Go to:
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C:\Users<YOUR_USERNAME>
Enable Hidden items
Find the folder:
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.ssh
Delete the entire .ssh folder
Empty the Recycle Bin
Why:
Old emulator keys
Corrupted Dev Manager keys
Conflicting identities
This is SAFE unless you actively use SSH for servers.
STEP 5: Re‑register the TV using CLI
Open Command Prompt:
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ares-setup-device
Choose:
Add device
Name: anything (example: LGTV)
Host: <TV_IP>
Port: 9922
Username: prisoner ✅ (this is NORMAL)
Passphrase:
STEP 6: Generate fresh SSH keys
Run:
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ares-device -i
Expected:
New folders like:
LGTV_webos
webos_emul
No “failed to get ssh private key” error
You can test with:
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ares-device-info
If it prints TV info → SSH is FIXED.
STEP 7: Windows Firewall check (TEMPORARY)
If things still fail:
Open Windows Defender Firewall
Temporarily disable Private network firewall
Retry the CLI connection
Re‑enable firewall after confirmation
You can also manually allow:
Node.js
webOS CLI
webOS Dev Manager
STEP 8: Use webOS Dev Manager
Open webOS Dev Manager
Connection mode:
✅ Use Developer Mode
❌ Homebrew / Root (unless rooted)
❌ Manual (not needed)
Enter:
Address: <TV_IP>
Passphrase:
If it says passphrase is wrong:
It usually isn’t
That error often means bad SSH keys, already fixed above
About “prisoner” username (IMPORTANT)
prisoner is normal
It is hard‑coded by LG
You do NOT change it
Dev Manager and CLI expect it
Emulator key question
You may see:
webos_emul
Deleting emulator keys is safe
Deleting .ssh entirely is the cleanest fix
And yes I used chatgpt to help me make this as I had used it to help me get past the "failed to fetch private key" and I used WhatsApp to tell my chatgpt the errors from my pc to my phone and moderators keep this here or put it somewhere better for people to access it.
Reproduction Steps
Just the thing above
Expected Behavior
After this everything should be fine, you might need an ethernet cable to connect your pc/laptop to the router, you don't need to connect your router to the lg TV.