40171: Token renewal not configured

The auth token expired and could not be renewed because no renewal mechanism was configured. Without an authCallback, authUrl, or API key, the Ably SDK has no way to obtain a replacement token.

What you should do

Configure the client so it can renew tokens. Set an authUrl, authCallback, or API key in the client options, and the SDK will obtain a fresh token automatically when the current one expires. A bare token literal can't be renewed once it expires.

Why it happens

The client was given only a token literal, with no authUrl, authCallback, or API key alongside it. When that token expired, the SDK had no configured way to obtain a replacement, so it couldn't continue.

What you'll see

The error is reported with code 40171 and HTTP status 403. The message is typically library initialized with a token literal without any way to renew the token when it expires (no authUrl, authCallback, or key).