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Troubleshooting

Common Exchange integration problems, starting with the one you'll hit most: authentication.

Find your symptom

Exchange: "Invalid client" or AADSTS700016
Wrong Client ID, Tenant ID, or expired Client Secret in the Azure app registration.
Exchange: "Insufficient privileges" or consent required
API permissions are set but admin consent was never granted in Azure AD.

Authentication failures​

Symptoms:

  • "Invalid client" or "Invalid client secret" errors
  • "AADSTS700016: Application not found in the directory"
  • "Insufficient privileges to complete the operation"
  • Authentication fails even though the credentials look correct

Cause: an incorrect Microsoft Entra ID app registration: wrong Client ID, Client Secret, or Tenant ID, or missing API permissions.

Work through the three checks below.

1. Verify Client ID, Client Secret, and Tenant ID​

These are the most frequently reported issues:

  1. Client ID (Application ID):

    • Go to Azure Portal > Microsoft Entra ID > App registrations.
    • Find your Dime.Scheduler app and copy the Application (client) ID.
    • Make sure it matches exactly what's in the Dime.Scheduler connector settings.

  2. Tenant ID:

    • On the same app overview page, copy the Directory (tenant) ID.
    • Make sure it matches Dime.Scheduler. A common mistake is using the wrong tenant ID when you have several.

  3. Client Secret:

    • Go to Certificates & secrets.
    • Check whether the secret has expired (secrets last 6, 12, or 24 months).
    • If it has, or you're unsure, create a new one.
    • Copy the secret value (not the Secret ID) immediately. You only see it once.
    • Update it in the Dime.Scheduler connector configuration.
warning

Client secrets expire. Set a reminder to rotate them before they do, to avoid service interruptions.

2. Verify API permissions​

The app must have the right permissions:

  1. Open your app > API permissions.
  2. Make sure these Microsoft Graph application permissions are present:
    • Calendars.ReadWrite - calendar sync
    • MailboxSettings.ReadWrite - mailbox configuration
    • User.Read.All - reading user information
  3. Click Grant admin consent for [Your Organization].
Admin consent is required

Adding the permissions is not enough. You must grant admin consent afterwards, or they won't take effect. This step is the one most often forgotten.

3. Update the Dime.Scheduler configuration​

  1. Open the Exchange setup page.
  2. In the Microsoft Entra ID section, enter:
    • Client ID: the Application (client) ID
    • Client Secret: the secret value (not the secret ID)
    • Tenant ID: the Directory (tenant) ID
  3. Save to apply the changes.