Troubleshooting & FAQ Leave feedback

Solutions to the most common GroupDocs.Signature MCP server issues — server not appearing in the client, startup failures, missing native dependencies, and first-launch timeouts.

Note

Platform-specific troubleshooting: runtime problems depend on which build you run. For the dnx runner, native graphics libraries, and the Docker channel, see Troubleshooting (.NET). The issues on this page apply to every platform.

1. Restart the client — every client reads its MCP config only at startup.
2. Check the config file location for your OS (per-client reference) and that the entry sits under the right root key (mcpServers for Claude Desktop/Cursor/Windsurf, servers for VS Code/VS 2022).
3. Validate the JSON — a trailing comma silently breaks the whole file. If you used the installer, a timestamped .bak of your previous config sits next to the file for comparison.

A cold cache: on the very first use the server’s package or image is still downloading while the client is already waiting on the connection. Warming it once fixes it for good — the exact command depends on your build: .NET.

These are properties of the build you run rather than of MCP, so the fixes live with the platform:

Pass the file name, not a full path from your machine: the server resolves names inside its configured storage folder. When a name is not found the tool responds with the list of files it can see, so the agent can correct itself — check that list against GROUPDOCS_MCP_STORAGE_PATH.

No. Text, QR code, barcode, and image signatures are visual marks — they carry information and are excellent for tracking, routing, and machine-readable references, but they do not prove who signed or that the file is unaltered. Only a digital signature, backed by a certificate, does that. Ask for type: "digital" when the legal property matters, and use verify or search_digital_signatures to check it.

On your machine. A digital signature takes a certificate file and its password, both resolved locally by the local server process — nothing about the certificate is transmitted anywhere. Treat the password like any other secret: prefer an environment variable over a literal in a committed client config, exactly as for metered keys.

Evaluation mode: only the first two pages are processed, and every page gets a trial badge. On a longer document that means a signature you asked for on page 5 silently never lands. Check with get_license_status before trusting any signing run.

search_qr_codes and search_barcodes read machine-readable codes; search_text_signatures finds embedded text stamps and labels — not ordinary body text; search_image_signatures returns embedded logos and stamp images as PNGs; search_digital_signatures returns certificate details. If you only want “is this signed and is it valid”, verify answers in one call.

Yes — signatures accumulate. Be aware that adding a visual signature to a digitally signed file invalidates the existing digital signature, because the bytes change. Sign digitally last.

Ask your agent “list your GroupDocs signature tools and the license status” — it should name sign, verify, search_digital_signatures, search_qr_codes, search_barcodes, search_text_signatures, search_image_signatures, get_document_info, get_license_status. For a scripted check that performs the real MCP handshake and a live call through the engine, see verifying a .NET installation.

Post your config (redact license paths) and the client name in the Signature forum — we answer MCP questions daily. Bugs: GitHub issues.