Resolve common issues with Azure Cosmos DB Shell installation, authentication, connections, and command execution.
Installation issues
Issue: "Command not found" (NuGet installation)
Error:
cosmosdbshell: command not found
Causes:
- .NET SDK not installed
- Tool not installed correctly
- PATH not updated
- Terminal not restarted after installation
Solutions:
Verify .NET SDK Installation
dotnet --version- Should show version 10.0 or later
- If not installed, install .NET SDK
Reinstall the Tool
dotnet tool uninstall --global CosmosDBShell dotnet tool install --global CosmosDBShell --prereleaseVerify Installation Location
dotnet tool list --global | grep CosmosDBShell- Should show:
cosmosdbshell 1.0.213-preview
- Should show:
Restart Terminal
- Close and reopen your terminal
- Terminal may cache PATH information
Add to PATH Manually (if needed)
- Windows: Add
%USERPROFILE%\.dotnet\toolsto PATH - macOS/Linux:
~/.dotnet/toolsshould already be in PATH
- Windows: Add
Issue: "File not found" (binary installation)
Error:
cosmosdbshell: No such file or directory
Causes:
- Archive didn't extract completely
- File not executable (Linux/macOS)
- Wrong file path
Solutions:
Verify Extraction
- Check all files were extracted
- Look for
cosmosdbshellexecutable (or.exeon Windows)
Make Executable (Linux/macOS)
chmod +x ~/cosmosdbshell/cosmosdbshellUse Full Path
/full/path/to/cosmosdbshellAdd to PATH
export PATH="$PATH:~/cosmosdbshell"
Issue: "File corrupted" during download
Error:
Archive is corrupted or incomplete
Causes:
- Incomplete download
- Network interruption
- Wrong file format
Solutions:
Download Again
- Delete corrupted file
- Re-download from official source
- Verify file size matches expected
Check MD5/SHA Hash
- Compare hash of downloaded file
- Matches hash provided on release page
Use Different Browser
- Try alternative download method
- Try different network connection
Authentication issues
Issue: "Authentication failed"
Error:
Authentication failed. Please check your credentials.
Causes:
- Expired token
- Wrong credentials
- No internet connection
- Account key incorrect
Solutions:
Try Entra ID (Recommended)
- Cosmos DB Shell should prompt for browser authentication
- Sign in with your Azure account
- Most reliable method
Check Internet Connection
ping azure.microsoft.com- Ensure network connectivity
Verify Account Key
- Go to Azure portal
- Navigate to Cosmos DB account
- Copy Primary Connection String
- Verify format is correct
Clear Cached Credentials
- Windows:
credman(Credential Manager) - macOS: Keychain
- Linux: Check ~/.config directory
- Windows:
Issue: "Unauthorized - insufficient permissions"
Error:
Authorization failed. Your user does not have permission to perform this operation.
Causes:
- User lacks necessary RBAC roles
- Role not assigned to account
- Wrong subscription context
Solutions:
Check RBAC Roles
- Go to Azure portal > Cosmos DB Account
- Access Control (IAM)
- Verify your user has "Cosmos DB Account Reader" or higher role
Request Role Assignment
- Ask your subscription admin
- Assign appropriate role (see Security Best Practices)
Verify Subscription
az account show- Ensure you're in correct subscription
- Switch if needed:
az account set --subscription <ID>
Issue: "Token expired"
Error:
Token has expired. Please re-authenticate.
Causes:
- Session timeout
- Token expired after long inactivity
- Time synchronization issue
Solutions:
Re-authenticate
- Exit shell:
exit - Restart:
cosmosdbshell - Sign in again
- Exit shell:
Check System Time
- Ensure system clock is synchronized
- Windows: Settings > Time & Language > Date & Time
- macOS/Linux: Check system time with
date
Check Token Refresh Settings
- Tokens should auto-refresh
- If issue persists, contact Azure support
Connection issues
Issue: "Connection refused"
Error:
Connection refused to Cosmos DB account
Causes:
- Wrong endpoint URL
- Firewall blocking connection
- Network connectivity issue
- Account endpoint incorrect
Solutions:
Verify Endpoint URL
- Azure portal > Cosmos DB Account
- Copy correct endpoint URL
- Format:
https://<account>.documents.azure.com:443/
Check Firewall
- Verify IP allowed in Cosmos DB firewall rules
- Azure portal > Cosmos DB Account > Firewall and virtual networks
- Add your IP if needed
Test Network Connectivity
ping <account>.documents.azure.com- Should respond with IP address
Check VPN/Proxy
- If using VPN, ensure it's connected
- If using proxy, verify proxy settings
Issue: "Cannot resolve endpoint"
Error:
Cannot resolve host: account.documents.azure.com
Causes:
- DNS resolution failure
- Wrong endpoint name
- Network connectivity
- Firewall blocking DNS
Solutions:
Verify Endpoint Spelling
- Double-check account name
- Correct format:
https://<account>.documents.azure.com:443/
Check DNS
nslookup <account>.documents.azure.com- Should return IP address
Try Alternative DNS
- Use public DNS (8.8.8.8, 1.1.1.1)
- Check ISP DNS settings
Test Direct Connection
telnet <account>.documents.azure.com 443- Should connect successfully
Issue: "Timeout connecting to Cosmos DB"
Error:
Connection timeout. Could not connect to Cosmos DB account.
Causes:
- Network latency
- Slow internet connection
- Cosmos DB service issue
- Firewall blocking traffic
Solutions:
Increase Timeout
- Modify connection timeout in settings
- Default is 30 seconds
Check Network Speed
- Test bandwidth with speed test
- Ensure sufficient bandwidth
Try Different Network
- Switch to different Wi-Fi or mobile hotspot
- Test if issue is network-specific
Check Azure Status
- Go to Azure Status Page
- Verify Cosmos DB service is operational
Command issues
Issue: "Command not recognized"
Error:
Unknown command. Type 'help' for available commands.
Causes:
- Typo in command name
- Command not supported in current version
- Using wrong syntax
Solutions:
Check Command Syntax
- Use
helpto list available commands - Use
help <command>for specific command help
- Use
Verify Command Spelling
> help query- Correct:
query, notselectorfind
- Correct:
Check Your Version
> version- Ensure you have latest version
Issue: "Syntax error in query"
Error:
Syntax error in SQL query
Causes:
- Invalid SQL syntax
- Missing quotes
- Incorrect JSON path
- Unsupported SQL function
Solutions:
Review SQL Syntax
- Verify query is valid SQL (not NoSQL)
- Example:
SELECT * FROM c WHERE c.status = 'active' - Not valid:
db.collection.find({})
Check String Quotes
- Use single quotes in queries
- String values:
'value' - JSON keys:
"key"
Validate JSON Path
- Correct:
c.address.city - Not valid:
c.address[0].city(without proper syntax)
- Correct:
Test Query in Azure portal
- Verify query works in Data Explorer first
- Copy working query to shell
Issue: "No documents returned"
Error:
CS > query "SELECT * FROM c"
(empty result)
Causes:
- Container is empty
- Query filter too restrictive
- Wrong container
- Partition key mismatch
Solutions:
Verify Container Has Data
> query "SELECT COUNT(*) as count FROM c"- Should return count > 0
Check Container Name
> pwd- Verify you're in correct container
Simplify Query
# Start with simple query > query "SELECT TOP 1 * FROM c" # Then add filters > query "SELECT * FROM c WHERE c.status = 'active'"Review Partition Key
- Ensure partition key is included in query
- For better performance:
SELECT * FROM c WHERE c.id = 'value'
VS Code extension issues
Issue: Extension not appearing
Error:
Cannot find "Azure Cosmos DB Shell" in Extensions
Causes:
- VS Code version too old
- Extension not installed
- VS Code cache issue
Solutions:
Check VS Code Version
- Help > About
- Should be 1.85 or later
- Update if needed
Reinstall Extension
- Go to Extensions (Ctrl+Shift+X)
- Search "Cosmos DB"
- Click Install
Clear VS Code Cache
- Close VS Code
- Delete
.vscodefolder in user directory - Restart VS Code
Issue: Resource Explorer blank
Error:
Resource Explorer shows no databases or containers
Causes:
- Not authenticated
- No Cosmos DB accounts in subscription
- Wrong subscription selected
- Account has no databases
Solutions:
Verify Authentication
- Click Cosmos DB icon in sidebar
- Should show account selector
- Sign in if prompted
Check Subscription
- Verify correct subscription is selected
- Switch subscription if needed
Refresh Explorer
- Press F5 or click refresh icon
- Wait for data to load
Check Account Exists
- Go to Azure portal
- Verify Cosmos DB account exists
- Verify you have access to account
Issue: MCP server won't start in VS Code
Error:
Failed to start MCP server
Causes:
- Port already in use
- Invalid settings
- Cosmos DB Shell not properly installed
- Firewall blocking port
Solutions:
Check Port Availability
# Windows netstat -ano | findstr 6128 # macOS/Linux lsof -i :6128- If in use, kill process or use different port
Verify MCP Settings
- Open Settings (Ctrl+,)
- Search "Cosmos DB"
- Check
cosmosDB.shell.MCP.enabledis true
Try Different Port
{ "cosmosDB.shell.MCP.port": 6129 }Check Firewall
- Ensure firewall allows localhost connections
- Disable temporarily to test
MCP server issues
Issue: "MCP server not responding"
Error:
Cannot connect to MCP server
Causes:
- MCP server not running
- Wrong port
- Firewall issue
- Connection timeout
Solutions:
Verify MCP Server Running
curl http://localhost:6128/health- Should return JSON response
Check Configuration
- Verify
cosmosDB.shell.MCP.enabledis true - Check correct port in settings
- Verify
Restart MCP Server
- Command Palette (Ctrl+Shift+P)
- Type "Cosmos DB: Restart MCP Server"
Check Firewall
- Ensure localhost:6128 is accessible
- Disable firewall temporarily to test
Issue: "MCP port already in use"
Error:
Cannot bind MCP server to port 6128
Causes:
- Another process using port
- MCP server already running
- Port conflict
Solutions:
Stop Existing MCP Server
- Command Palette (Ctrl+Shift+P)
- Type "Cosmos DB: Stop MCP Server"
Find Process Using Port
# Windows netstat -ano | findstr 6128 taskkill /PID <PID> /F # macOS/Linux lsof -i :6128 kill -9 <PID>Use Different Port
{ "cosmosDB.shell.MCP.port": 6129 }
Performance issues
Issue: Shell is slow or unresponsive
Causes:
- Large query result set
- Slow network connection
- High system resource usage
- Cosmos DB service issue
Solutions:
Limit Query Results
> query "SELECT TOP 100 * FROM c"Add Filters to Query
> query "SELECT * FROM c WHERE c.status = 'active'"Check Network
- Test bandwidth
- Switch to different network
- Check latency with
ping
Monitor System Resources
- Check CPU usage
- Check memory usage
- Close unnecessary applications
Issue: Queries timeout
Error:
Query timeout. Please try again.
Causes:
- Large result set
- Complex query
- Slow network
- Cosmos DB service overloaded
Solutions:
Increase Timeout Setting
- Settings (Ctrl+,)
- Search "Cosmos DB"
- Increase
cosmosDB.queryTimeout
Optimize Query
# Instead of SELECT * > query "SELECT c.id, c.name FROM c" # Add filters > query "SELECT * FROM c WHERE c.status = 'active'" # Use TOP > query "SELECT TOP 1000 * FROM c"Check Cosmos DB
- Verify service is operational
- Check Azure Status Page
Getting help
Check Docs
Azure Support
- For Cosmos DB service issues: Create support request