Connection and Authentication Errors

This page helps you troubleshoot connection and authentication issues with the SharePoint Connector.

Common Connection Errors

Error: Connection Failed

Symptoms:

• "Connection failed" message
• Unable to connect to SharePoint
• Connection attempt fails

Possible Causes and Solutions:

Cause	Solution
Incorrect Base URL	Verify URL format (must end with sharepoint.com)
Network issue	Check internet connectivity
SharePoint down	Verify SharePoint is accessible
Firewall blocking	Allow SharePoint URLs

Error: Access Denied

Symptoms:

• "Access denied" or "403 Forbidden"
• Can connect but can't access folders

Possible Causes and Solutions:

Cause	Solution
Insufficient permissions	Grant SharePoint permissions
Wrong site	Verify Subsite Name setting
Folder doesn't exist	Create the folder in SharePoint

Error: Site Not Found

Symptoms:

• "Site not found" or "404"
• URL appears correct

Possible Causes and Solutions:

Cause	Solution
Subsite Name has leading slash	Remove leading / (use sites/BCDocs not /sites/BCDocs)
Subsite Name incorrect	Verify format: sites/name, teams/name, or just name for root subsites
Site doesn't exist	Verify site exists in SharePoint
Typo in URL	Review all URL components

Subsite Name Format Examples:

Correct	Incorrect
sites/BCDocs	/sites/BCDocs
teams/BCDocs	/teams/BCDocs
BCDocs	/BCDocs

Authentication Errors

Error: Authentication Failed

Symptoms:

• Can't authenticate
• OAuth errors
• "AADSTS" error codes

Possible Causes and Solutions:

Cause	Solution
Wrong credentials	Verify Client Id and Client Secret Value
Expired secret	Generate new client secret (App Registration, Modern App Registration)
Missing consent	Grant admin consent
Wrong tenant	Verify you're in correct tenant
Single-tenant app registration, Entra Tenant Id blank (PKCE, Modern App Registration)	Fill in Entra Tenant Id (AADSTS50194)
Pop-up blocked (PKCE, Modern App Registration, App Registration)	Allow pop-ups for Business Central, or click Sign in on the PKCE sign-in page

Error: Token Expired

Symptoms:

• Was working, now fails
• "Token expired" message

Solutions:

1. Click "Connect" to re-authenticate
2. For personal auth, user must reconnect
3. Check if refresh token is still valid

Error: Invalid Client

Symptoms:

• "AADSTS700016" or similar
• "Invalid client" message

Possible Causes and Solutions:

Cause	Solution
Wrong Client ID	Copy correct ID from Azure
App deleted	Recreate app registration
Wrong tenant	Verify app is in your tenant

Error: Redirect URI Mismatch

Symptoms:

• "AADSTS50011"
• "Reply URL does not match"

Solution:

1. Go to Azure AD app registration
2. Check redirect URIs
3. Ensure exact match with BC Callback URL
4. App Registration: include the page=70319501 parameter. Modern App Registration and PKCE: use the OAuthLanding.htm page shown as Callback URL

Error: Redirect URL Registered Under the Wrong Platform (PKCE)

Symptoms:

• "The redirect URL ... is registered under the wrong platform on the App Registration ..."
• "AADSTS7000218" or "AADSTS9002327"

Cause: PKCE is used with your own app registration (Client Id filled in), and its redirect URI is registered under Web (which requires a client secret) or Single-page application.

Solution:

1. In the app registration, open Authentication
2. Remove the OAuthLanding.htm URL from the Web and Single-page application platforms
3. Add it under Mobile and desktop applications (custom redirect URI)
4. Set Allow public client flows to Yes
5. Or clear Client Id to use the connector's app registration

Error: Sign-In Not Completed

Symptoms:

• PKCE: the sign-in page closes, or "The sign-in response does not belong to this sign-in (state mismatch), please try again."
• PKCE: "The sign-in failed: ..." followed by the error from Microsoft Entra
• Modern App Registration: "The sign-in was not completed."

Solution:

1. Close all open Microsoft sign-in windows
2. Click Connect again and finish the sign-in in the new window
3. For "The sign-in failed", look up the AADSTS code in the message (see the table below)

Error: No Refresh Token

Symptoms:

• "The Microsoft login server did not return a refresh token, the connection cannot be kept without signing in again." (PKCE)
• "The sign-in succeeded, but no refresh token could be read from it and the access token cannot be renewed from the token cache either, ..." (Modern App Registration)

Solution: With your own app registration, make sure the delegated SharePoint permission is consented and that no policy removes offline_access. Then click Connect again. Modern App Registration checks the renewal during Connect, so this error appears right away instead of users being asked to sign in on every page later.

Configuration Errors

Error: Server Relative URLs

Symptoms:

• "Server relative urls must start with SPWeb" (returned by the SharePoint service, not a connector message)

Possible Causes and Solutions:

Cause	Solution
Base Folder format	Don't use full URLs in Base Folder
URL encoding	Remove %20 and use spaces
Wrong path	Verify folder path format

Error: Folder Not Found

Symptoms:

• "Folder not found"
• Path seems correct

Possible Causes and Solutions:

Cause	Solution
Folder doesn't exist	Create folder in SharePoint
Path format wrong	Check for leading slashes
Different site	Verify you're looking at right site

Error: Invalid Path Characters

Symptoms:

• Upload fails
• Folder creation fails

Solutions:

1. Check folder/file names for special characters
2. Enable "Strict" name sanitizing
3. Remove problematic characters from names

Network and Connectivity

Timeout Errors

Symptoms:

• Operations timeout
• Slow responses
• Intermittent failures

Solutions:

Action	How
Check network	Test SharePoint directly
Reduce batch size	For bulk operations
Check proxy	If using proxy server
Off-peak hours	Try during low usage

Firewall Issues

Required Endpoints:

Endpoint	Purpose
*.sharepoint.com	SharePoint REST API
login.microsoftonline.com	OAuth (Public cloud)
login.microsoftonline.us	OAuth (US Government cloud)
check.hougaardlicense.com	License validation (production only)

Ensure outbound HTTPS (443) is allowed.

Diagnostic Steps

Step 1: Verify Connection

1. Open SharePoint Setup
2. Attempt to connect or browse SharePoint
3. Note any error message

Step 2: Test SharePoint Directly

1. Open browser
2. Navigate to SharePoint URL
3. Verify you can access the site
4. Try the Base Folder path

Step 3: Check Azure AD

1. Go to Azure portal
2. Find your app registration
3. Verify settings match BC
4. Check for expired secrets

Step 4: Review Permissions

1. Check API permissions granted
2. Verify admin consent
3. Check SharePoint site permissions

Error Message Reference

AADSTS Error Codes

Code	Meaning	Solution
AADSTS50011	Redirect mismatch	Fix redirect URI
AADSTS65001	Consent required	Grant admin consent
AADSTS70011	Invalid scope	Check permissions
AADSTS700016	App not found	Verify Client ID
AADSTS700027	Client assertion failed (Certificate)	Upload the current certificate to the app registration
AADSTS50194	Single-tenant app signed in through the common endpoint	Fill in Entra Tenant Id (PKCE, Modern App Registration)
AADSTS7000218	Client secret expected (PKCE with a Web redirect URI)	Register the redirect URI under Mobile and desktop applications
AADSTS9002327	Single-page application redirect URI (PKCE)	Register the redirect URI under Mobile and desktop applications

SharePoint Errors

Error	Meaning	Solution
401 Unauthorized	Auth failed	Re-authenticate
403 Forbidden	No permission	Grant access
404 Not Found	Path wrong	Check URL/path
429 Too Many Requests	Rate limited	Slow down

Resolution Checklist

Quick Checks

• Base URL ends with sharepoint.com
• Subsite Name has no leading slash
• Base Folder has no URL encoding
• Client ID is correct GUID
• Client Secret Value is the value (not ID)
• Callback URL matches Azure exactly
• Admin consent granted

If Still Failing

1. Reset connection in SharePoint Setup
2. Re-enter credentials
3. Reconnect
4. Test again

Getting Help

If issues persist:

1. Document the error message
2. Note when it started
3. Record what changed recently
4. Contact support with details

Related Topics

• SharePoint Setup Page
• Authentication Methods
• Authentication Tips and Tricks
• Microsoft Entra App Registration
• Common Issues and Solutions