validator registration not working on 1.9rc3 [Teku]

[tbenr]

on 1.9rc2

at startup teku tries to post ssz content and immediately fallback to JSON, which works

{"@timestamp":"2025-04-15T10:00:33,745","level":"DEBUG","thread":"OkHttp http://127.0.0.1:18550/...","class":"RestBuilderClient","message":"Failed to register validator using SSZ. Will retry using JSON (error: {"code":400,"message":"invalid character 'ò' looking for beginning of value"})","throwable":""}
{"@timestamp":"2025-04-15T10:00:33,889","level":"INFO","thread":"validator-async-2","class":"teku-validator-log","message":"Validator   *** 24 out of 24 validator registration(s) were successfully sent to the builder network via the Beacon Node.","throwable":""}

on 1.9rc3 the endpoint keep failing with the same 502 despite the fallback is happening as before

{"@timestamp":"2025-04-15T09:48:59,515","level":"DEBUG","thread":"OkHttp http://127.0.0.1:18550/...","class":"RestBuilderClient","message":"Failed to register validator using SSZ. Will retry using JSON (error: {"code":502,"message":"no successful r
elay response"})","throwable":""}
{"@timestamp":"2025-04-15T09:48:59,561","level":"INFO","thread":"validator-async-3","class":"teku-validator-log","message":"Validator   *** 0 out of 24 validator registration(s) were successfully sent to the builder network via the Beacon Node.","t
hrowable":""}
{"@timestamp":"2025-04-15T09:48:59,561","level":"ERROR","thread":"validator-async-3","class":"teku-validator-log","message":"Validator   *** Failed to send validator registrations to the builder network via the Beacon Node","throwable":" java.util.
concurrent.CompletionException: tech.pegasys.teku.ethereum.executionclient.response.InvalidRemoteResponseException: Invalid remote response from the builder: {\"code\":502,\"message\":\"no successful relay response\"}\n\tat java.base/java.util.conc
....}
{"@timestamp":"2025-04-15T09:48:59,563","level":"INFO","thread":"validator-async-3","class":"ValidatorRegistrator","message":"Will retry to register validators in 30 seconds","throwable":""}

[tbenr]

not that meaningful debug logs from mev-boost

time="2025-04-15T09:40:18.288Z" level=debug msg="handling request" method=registerValidator version=v1.9-rc3
time="2025-04-15T09:40:18.329Z" level=info msg="http: POST /eth/v1/builder/validators 502" duration=0.041397 method=POST path=/eth/v1/builder/validators status=502 version=v1.9-rc3
time="2025-04-15T09:40:24.002Z" level=debug msg="checking relay status" url="https://boost-relay-sepolia.flashbots.net/eth/v1/builder/status" version=v1.9-rc3
time="2025-04-15T09:40:24.032Z" level=debug msg="relay status OK" url="https://boost-relay-sepolia.flashbots.net/eth/v1/builder/status" version=v1.9-rc3
time="2025-04-15T09:40:24.032Z" level=info msg="http: GET /eth/v1/builder/status 200" duration=0.030283 method=GET path=/eth/v1/builder/status status=200 version=v1.9-rc3
time="2025-04-15T09:40:24.73Z" level=debug msg="handling request" method=registerValidator version=v1.9-rc3
time="2025-04-15T09:40:24.813Z" level=info msg="http: POST /eth/v1/builder/validators 502" duration=0.083659 method=POST path=/eth/v1/builder/validators status=502 version=v1.9-rc3
time="2025-04-15T09:40:36.002Z" level=debug msg="checking relay status" url="https://boost-relay-sepolia.flashbots.net/eth/v1/builder/status" version=v1.9-rc3

[tbenr]

Closing because we found that it was a relay issue which was rejecting a POST with application/json; charset=utf-8 as content type. Removing ; charset=utf-8 seems to work.

It seems a valid issue on the relay side thou.

[metachris]

will be resolved with https://github.com/flashbots/mev-boost-relay/pull/707