ERR_NGROK_378: The header value for HEADERKEY beginning with PREFIX...' exceeds the maximum header value length of BYTES bytes - ngrok documentation

What does ERR_NGROK_378 mean?

ngrok returns ERR_NGROK_378 with this message:

The header value for <HEADERKEY> beginning with <PREFIX>...' exceeds the maximum header value length of <BYTES> bytes.

Where can I get more help with ERR_NGROK_378?

Email support@ngrok.com and include the error code.