Troubleshooting

What to check when a server doesn’t show up, a tool is missing, a change didn’t apply or an AI app doesn’t go through Delta MCP.

On this page

Find your symptom, then read the cause and what to do.

See what Delta MCP sees

mcpdelta diagnose --list   # the servers it finds
mcpdelta diagnose          # starts each to read its tools

diagnose only reads: it lists tools and never calls one. It waits 45 seconds for a local command, 15 for a remote server. It prints connexion requise (sign in first), pas de réponse (no answer), commande introuvable (command not found) or serveur injoignable (nothing answers). The command line speaks French for now.

A server doesn’t show up

Symptom	Cause	What to do
Missing from the list	Its entry is marked `"disabled": true`, or it’s a paused Claude Desktop extension	Turn it on in that app.
A warning names a file	Its JSON isn’t valid	Fix it, or copy a dated version back from `backups` (Where your data lives).
“Stays in Claude”, “Claude’s own connector”	Gmail, Google Calendar and Google Drive run inside Claude, with no address	Nothing to do: they can’t go through Delta MCP.
“Stays in Claude”, “Claude doesn’t keep its address”	A claude.ai connector this computer has no address for	Add it by its address under Connectors, then turn the original off in Claude.
A Codex or Zed server stays direct	Delta MCP doesn’t change those apps’ settings yet	See Supported AI apps.

A server that is missing in the app itself, not only in Delta MCP? The checks that apply to any AI app are in Why does your MCP server not show up?.

A connector doesn’t answer

You see, or your AI reports	Cause	What to do
Not signed in, `needs a login`	The sign-in was never made, or ended	Choose Sign in. Nothing to restart.
`could not renew its sign-in`	The network or the service failed	Try again in a moment. There is nothing to sign in.
“didn’t answer in time”, “can’t start it or reach it”	Slow, stuck, command not found, or nothing at its address	Choose Try again. Check that its command runs in a terminal.
“answered with an error”	The server started, then failed	Read its own message.

A tool is missing

Your AI sees three tools. Every original tool stays callable by name: ask it to look the tool up with delta_read (The three tools). If it still can’t use it:

Your AI reports	Cause	What to do
`is switched off by the user`	You turned that action off under Connectors	Turn it back on.
`unknown tool`, `no such tool`	A typo, or the server renamed or removed it	Use the name it suggests. A renamed tool keeps your setting.
`was removed`	You put the connector back in your apps	Add it again under Connectors.

A change didn’t apply

What you see	Cause	What to do
Waiting for you	The connector’s mode asks first	Answer on the card at the top right of your screen (a browser page on Windows and Linux).
Refused	You refused the card, or the connector is Read only	Change its mode.
Couldn’t finish	A call failed part-way. Calls already made stay made	Open it in Activity, then Undo or ask your AI to finish.
`got no answer`, `was restarted`	A server stopped answering	The change may have gone through: check before repeating it.
Not all of it could be put back	Something changed since	Undo the later task first.
`settings are busy`	Two changes at once	Try again in a minute. Nothing changed.

An AI app doesn’t go through Delta MCP

Restart it: an app reads its settings when it starts. Quit and reopen Claude Desktop, start a new conversation in Claude Code, reopen the others.
Open Connectors. “Uses its own copy” means that app still runs the server directly. Check Used in: an app you unchecked keeps its copy.
If your AI sees a connector twice, its original is still on: turn it off in Claude (Settings, Connectors), or turn off its Claude Code plugin.
For Claude Code, Delta MCP uses the claude command. If it isn’t found, check that claude runs in a terminal.

Updated 7 October 2026 Something missing or wrong? Open an issue