mcp-nextcloud/docs/troubleshooting.md

Troubleshooting

This guide covers common issues and solutions for the Nextcloud MCP server.

Multi-user / Login Flow v2 issues? See the Login Flow v2 troubleshooting section for app-password storage, provisioning loops, and OAuth issuer problems.

Upgrading from v0.57.x? See the Configuration Migration Guide for help with new variable names.

Configuration Issues (v0.58.0+)

Issue: Deprecation warning for VECTOR_SYNC_ENABLED

Symptom:

WARNING: VECTOR_SYNC_ENABLED is deprecated. Please use ENABLE_SEMANTIC_SEARCH instead.

Cause: You're using the old variable name from v0.57.x.

Solution:

# In your .env file, replace:
VECTOR_SYNC_ENABLED=true

# With:
ENABLE_SEMANTIC_SEARCH=true

See Configuration Migration Guide for complete migration instructions.

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Issue: Deprecation warning for ENABLE_OFFLINE_ACCESS

Symptom:

WARNING: ENABLE_OFFLINE_ACCESS is deprecated. Please use ENABLE_BACKGROUND_OPERATIONS instead.

Cause: You're using the old variable name from v0.57.x.

Solution:

If you have semantic search enabled:

# In multi-user modes, you can remove ENABLE_OFFLINE_ACCESS entirely!
# ENABLE_SEMANTIC_SEARCH automatically enables background operations

# Before (v0.57.x):
ENABLE_OFFLINE_ACCESS=true
VECTOR_SYNC_ENABLED=true

# After (v0.58.0+):
ENABLE_SEMANTIC_SEARCH=true  # This is all you need!

If you only want background operations (no semantic search):

# Replace:
ENABLE_OFFLINE_ACCESS=true

# With:
ENABLE_BACKGROUND_OPERATIONS=true

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Issue: "Invalid MCP_DEPLOYMENT_MODE"

Symptom:

ValueError: Invalid MCP_DEPLOYMENT_MODE: 'oauth'. Valid values: single_user_basic, multi_user_basic, login_flow_v2

Cause: Invalid value for MCP_DEPLOYMENT_MODE.

Solution: Use one of the valid mode values:

MCP_DEPLOYMENT_MODE=single_user_basic   # Single-user with username/app password
MCP_DEPLOYMENT_MODE=multi_user_basic    # Multi-user BasicAuth pass-through
MCP_DEPLOYMENT_MODE=login_flow_v2       # Multi-user via Login Flow v2 (recommended)

Or remove MCP_DEPLOYMENT_MODE to use automatic detection.

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Issue: Missing TOKEN_ENCRYPTION_KEY when semantic search enabled

Symptom:

Error: [login_flow_v2] TOKEN_ENCRYPTION_KEY is required when ENABLE_SEMANTIC_SEARCH is enabled

Cause: In multi-user modes, semantic search automatically enables background operations, which require encrypted token storage.

Solution: Generate an encryption key and add required token storage configuration:

# Generate encryption key
python -c "from cryptography.fernet import Fernet; print(Fernet.generate_key().decode())"

# Add to .env:
TOKEN_ENCRYPTION_KEY=<generated-key>
TOKEN_STORAGE_DB=/app/data/tokens.db

Why this happens:

• v0.58.0+ automatically enables background operations when ENABLE_SEMANTIC_SEARCH=true in multi-user modes
• Background operations need encrypted refresh token storage
• This simplifies configuration but requires the encryption infrastructure

See Configuration Guide - Semantic Search for details.

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Issue: Both old and new variable names set

Symptom:

WARNING: Both ENABLE_SEMANTIC_SEARCH and VECTOR_SYNC_ENABLED are set. Using ENABLE_SEMANTIC_SEARCH.

Cause: You have both the old and new variable names in your configuration.

Solution: Remove the old variable name:

# Remove this line:
VECTOR_SYNC_ENABLED=true

# Keep this line:
ENABLE_SEMANTIC_SEARCH=true

The server will use the new name and ignore the old one, but it's cleaner to remove the old variable entirely.

---

Multi-User / Login Flow v2 Issues

For multi-user deployment issues — provisioning loops, app-password storage, OAuth issuer endpoints, scope enforcement — see the Login Flow v2 troubleshooting section.

Switching deployment modes

# To Single-User BasicAuth: set NEXTCLOUD_USERNAME and NEXTCLOUD_PASSWORD
# To Multi-User BasicAuth pass-through: MCP_DEPLOYMENT_MODE=multi_user_basic (no creds)
# To Login Flow v2: MCP_DEPLOYMENT_MODE=login_flow (no creds; also the default fallback)

Restart the server after changing modes. The active mode is logged at startup; you can also set MCP_DEPLOYMENT_MODE explicitly to fail fast if the env vars don't match.

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Configuration Issues

Issue: Environment variables not loaded

Cause: Environment variables from .env file are not loaded into the shell.

Solution:

On Linux/macOS:

# Load all variables from .env
export $(grep -v '^#' .env | xargs)

# Verify variables are set
env | grep NEXTCLOUD

On Windows (PowerShell):

# Load variables from .env
Get-Content .env | ForEach-Object {
    if ($_ -match '^\s*([^#][^=]*)\s*=\s*(.*)$') {
        [Environment]::SetEnvironmentVariable($matches[1].Trim(), $matches[2].Trim(), "Process")
    }
}

# Verify variables are set
Get-ChildItem Env:NEXTCLOUD*

With Docker:

# Docker automatically loads .env when using --env-file
docker run -p 127.0.0.1:8000:8000 --env-file .env --rm \
  ghcr.io/cbcoutinho/nextcloud-mcp-server:latest

---

Issue: ".env file not found"

Cause: The .env file doesn't exist or is in the wrong location.

Solution:

# Create .env from sample
cp env.sample .env

# Edit with your Nextcloud details
nano .env  # or vim, code, etc.

# Ensure you're in the correct directory when running commands
pwd  # Should be in the project directory containing .env

---

Issue: "Invalid Nextcloud credentials"

Cause: BasicAuth credentials are incorrect or the app password has been revoked.

Solution:

1. Verify username:

   # Username should match your Nextcloud login
   echo $NEXTCLOUD_USERNAME
   

2. Generate a new app password:

   • Log in to Nextcloud
   • Go to Settings → Security
   • Under "Devices & sessions", create a new app password
   • Update .env with the new password

3. Test credentials manually:

   curl -u "$NEXTCLOUD_USERNAME:$NEXTCLOUD_PASSWORD" \
     "$NEXTCLOUD_HOST/ocs/v2.php/cloud/capabilities" \
     -H "OCS-APIRequest: true"
   # Should return XML with capabilities
   

---

Server Issues

Issue: "Address already in use" / Port conflict

Cause: Another process is using port 8000.

Solution:

Option 1: Use a different port

uv run nextcloud-mcp-server --port 8080

Option 2: Find and kill the process using the port

# On Linux/macOS
lsof -ti:8000 | xargs kill -9

# On Windows
netstat -ano | findstr :8000
taskkill /PID <pid> /F

Option 3: Stop other MCP server instances

# Check for running instances
ps aux | grep nextcloud-mcp-server

# Kill specific process
kill <pid>

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Issue: Server starts but can't connect

Cause: Server is bound to localhost only, or firewall is blocking connections.

Solution:

1. Check server binding:

   # Bind to all interfaces to allow network access
   uv run nextcloud-mcp-server --host 0.0.0.0 --port 8000
   

2. Test connectivity:

   # Test from same machine
   curl http://localhost:8000/health/live
   
   # Test from network (if using --host 0.0.0.0)
   curl http://<server-ip>:8000/health/live
   

3. Check firewall:

   # Linux (ufw)
   sudo ufw allow 8000/tcp
   
   # Linux (firewalld)
   sudo firewall-cmd --add-port=8000/tcp --permanent
   sudo firewall-cmd --reload
   

---

Issue: Server crashes or restarts frequently

Cause: Various issues including memory limits or uncaught exceptions.

Solution:

1. Check logs with debug level:

   uv run nextcloud-mcp-server --log-level debug
   

2. Monitor resource usage:

   # Check memory and CPU
   top -p $(pgrep -f nextcloud-mcp-server)
   

3. Use process manager for automatic restart:

   # With systemd (see Running guide for full config)
   sudo systemctl restart nextcloud-mcp
   
   # With Docker Compose (includes restart: unless-stopped)
   docker-compose up -d
   

---

Connection Issues

Issue: MCP client can't authenticate

Cause: Auth flow failing or credentials invalid.

Solution:

For BasicAuth modes:

1. Verify credentials work:

   curl -u "$NEXTCLOUD_USERNAME:$NEXTCLOUD_PASSWORD" \
     "$NEXTCLOUD_HOST/ocs/v2.php/cloud/capabilities" \
     -H "OCS-APIRequest: true"
   

For Login Flow v2 mode:

1. Verify the server starts the OAuth issuer:

   uv run nextcloud-mcp-server --oauth --log-level debug
   # Look for "OAuth initialization complete"
   

2. Verify NEXTCLOUD_MCP_SERVER_URL matches the URL clients use to connect:

   echo $NEXTCLOUD_MCP_SERVER_URL
   

3. See Login Flow v2 troubleshooting for app-password and provisioning issues.

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Issue: Tools return errors or don't work

Cause: Missing Nextcloud apps, incorrect permissions, or API issues.

Solution:

1. Verify required Nextcloud apps are installed:

   • Notes: Install "Notes" app
   • Calendar: Ensure CalDAV is enabled
   • Contacts: Ensure CardDAV is enabled
   • Deck: Install "Deck" app

2. Check user permissions:

   • Ensure the authenticated user has access to the resources
   • Check sharing permissions for shared resources

3. Test API directly with Basic Auth:

   curl -u "$NEXTCLOUD_USERNAME:$NEXTCLOUD_PASSWORD" \
     "$NEXTCLOUD_HOST/apps/notes/api/v1/notes"
   

4. Check server logs for specific errors:

   uv run nextcloud-mcp-server --log-level debug
   

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Getting Help

If you continue to experience issues:

1. Enable Debug Logging

uv run nextcloud-mcp-server --log-level debug

Review the logs for specific error messages.

2. Test Nextcloud Connectivity

# Verify Nextcloud is reachable from the MCP server
curl -I "$NEXTCLOUD_HOST/status.php"

# With Basic Auth (Single-User or Multi-User BasicAuth modes)
curl -u "$NEXTCLOUD_USERNAME:$NEXTCLOUD_PASSWORD" \
  "$NEXTCLOUD_HOST/ocs/v2.php/cloud/capabilities?format=json" \
  -H "OCS-APIRequest: true"

For Login Flow v2 mode, see Login Flow v2 troubleshooting.

3. Check Versions

# MCP Server version
uv run nextcloud-mcp-server --version

# Python version
python3 --version

# Nextcloud version (check in admin panel)

4. Open an Issue

If problems persist, open an issue on the GitHub repository with:

• Server logs (with --log-level debug)
• Nextcloud version
• Deployment mode (single_user_basic / multi_user_basic / login_flow_v2)
• Error messages
• Steps to reproduce
• Environment details (OS, Python version, Docker vs local)

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See Also

• Authentication - Authentication modes
• Login Flow v2 - Multi-user setup, scope reference, troubleshooting FAQ
• Configuration - Environment variables
• Running the Server - Server options