Troubleshooting

Troubleshooting

Most failures here produce no error message.

Installing

Symptom	Cause
Descriptor opens as a page of text	Wrong MIME type — must be text/vnd.sun.j2me.app-descriptor
Install fails, no explanation	MIDlet-Jar-Size does not match the jar; usually a cache serving an old descriptor
Browser will not load the page	The hostname redirects to HTTPS
907 Invalid JAR — missing stack map	The jar was not preverified — see Building
"Already installed"	The descriptor's version must be higher, not equal

Connecting

Symptom	Cause
"no transport reached host:port"	Nothing answered. Check Wi-Fi; a handset on mobile data cannot see your LAN
"HOST KEY ... HAS CHANGED"	Server rebuilt, or interception. No way past by design — delete the connection and recreate it
A key that works from a laptop is refused	It is RSA, or has a passphrase, or is not in authorized_keys
Connects, then a blank screen	Try a different Terminal size

Through a bridge

Symptom	Cause
"this is not an authenticating bridge"	The far side is a plain proxy — clear Bridge key
"the bridge refused the key"	Does not match psk; compared exactly, so a pasted space counts
"no such target"	Not in targets — reopen Bridge target to refetch
"Could not ask the bridge"	Unreachable
Drops after a minute idle	nginx proxy_read_timeout — set 86400s
Works on the LAN, not outside	The proxy is not passing the WebSocket upgrade

Check a bridge is alive:

curl -s -o /dev/null -w '%{http_code}\n' \
  -H 'Connection: Upgrade' -H 'Upgrade: websocket' \
  -H 'Sec-WebSocket-Key: dGhlIHNhbXBsZSBub25jZQ==' \
  -H 'Sec-WebSocket-Version: 13' http://ssh.example.com/

101 = alive. It then closes, which is correct — curl has no key.

Keyboard

Wrong or dead keys are known — #11. Keys in the session menu shows raw codes; those measurements are what the issue needs.

Anything else: open an issue with the model, OS version, and what the status line said.