jina: Gateway error: received an empty stream from the client

Description

I encountered an error in flow.post method while trying to run python app.py -t index in multires-lyrics-search after cloning this repository: examples. The error message was: gateway@61291[E]:receive an empty stream from the client! please check your client's inputs, you can use "Client.check_input(inputs)".

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Environment

• jina 2.0.18
• jina-proto 0.0.85
• jina-vcs-tag (unset)
• libzmq 4.3.4
• pyzmq 1.21.5
• protobuf 3.20.0
• proto-backend cpp
• grpcio 1.44.0
• pyyaml 6.0
• python 3.7.13
• platform Linux
• platform-release 5.10.105-1-MANJARO
• platform-version #1 SMP PREEMPT Fri Mar 11 14:12:33 UTC 2022
• architecture x86_64
• processor
• uid 5025763201072
• session-id 7d472a12-b722-11ec-a806-049226d49030
• uptime 2022-04-08T15:58:49.863145
• ci-vendor (unset)

• JINA_ARRAY_QUANT (unset)
• JINA_CONTROL_PORT (unset)
• JINA_DEFAULT_HOST (unset)
• JINA_DISABLE_UVLOOP (unset)
• JINA_FULL_CLI (unset)
• JINA_HUBBLE_REGISTRY (unset)
• JINA_HUB_CACHE_DIR (unset)
• JINA_HUB_ROOT (unset)
• JINA_LOG_CONFIG (unset)
• JINA_LOG_ID (unset)
• JINA_LOG_LEVEL (unset)
• JINA_LOG_NO_COLOR (unset)
• JINA_LOG_WORKSPACE (unset)
• JINA_OPTIMIZER_TRIAL_WORKSPACE(unset)
• JINA_POD_NAME (unset)
• JINA_RANDOM_PORT_MAX (unset)
• JINA_RANDOM_PORT_MIN (unset)
• JINA_VCS_VERSION (unset)
• JINA_MP_START_METHOD (unset)