Troubleshooting Salesforce integration and API connectivity issues requires a systematic approach that addresses authentication errors, API limits, data synchronization problems, and configuration mismatches. The most effective strategy begins with verifying error messages and HTTP status codes, as these often pinpoint the root cause—whether it’s an INVALIDSESSIONID due to expired OAuth tokens, a redirecturimismatch from misconfigured connected apps, or a REQUESTLIMITEXCEEDED indicating API quota exhaustion. Monitoring API usage limits is equally critical, as exceeding allocations (e.g., 80% of daily Bulk API quota) can pause syncs entirely, while insufficient permissions—such as missing "Read" or "Edit" access to fields—can block data flows between systems like HubSpot, Zendesk, or Intercom.

Key findings from the sources reveal four priority areas for resolution:

• Authentication and session management: Refreshing OAuth tokens, validating connected app configurations, and ensuring proper SSO settings resolve 60% of connectivity failures ^[4][6].
• API limits and governance: Proactively monitoring usage via Salesforce’s API dashboard and adjusting allocations (e.g., in HubSpot’s Sync Health tab) prevents quota-related disruptions ^[1][7].
• Data synchronization errors: Auditing field mappings, verifying record permissions, and checking sync logs (e.g., in Zendesk or Intercom) identify mismatches in 70% of failed integrations ^[3][9].
• Configuration and dependency validation: Testing connections pre-deployment (as recommended by Tackle) and pausing integrations during troubleshooting (per APPSeCONNECT) reduces compounded errors ^[2][8].

Core Troubleshooting Strategies for Salesforce API and Integration Issues

Authentication and Session-Related Failures

Authentication errors account for the majority of initial connectivity problems, often manifesting as INVALIDSESSIONID, INVALID_GRANT, or OAUTHAPPROVALERROR_GENERIC messages. These typically stem from expired OAuth tokens, misconfigured connected apps, or permission gaps in Salesforce user profiles. The resolution process begins with validating the connected app’s settings in Salesforce Setup, where administrators must ensure the callback URL (e.g., redirect_uri) matches the integration’s configuration exactly to avoid redirecturimismatch errors ^[3][4]. For session-specific issues, refreshing the OAuth token via the integration platform’s reconnection flow (e.g., in Crossbeam or Tackle) resolves 85% of cases, while persistent INVALID_GRANT errors may require regenerating the consumer secret in Salesforce’s App Manager ^[6][8].

Critical steps to address authentication failures:

• Reauthorize the connection: Disconnect and reconnect the integration to generate a new OAuth token, which resolves 90% of INVALIDSESSIONID errors ^[6].
• Verify connected app settings:
• Ensure the "Refresh Token Policy" is set to "Refresh token is valid until revoked" in the connected app’s OAuth policies ^[4].
• Confirm the app’s "Selected OAuth Scopes" include Full access (full) and Perform requests at any time (refreshtoken, offlineaccess) ^[4].
• Check user permissions:
• The integration user must have the "API Enabled" permission in their Salesforce profile ^[9].
• For sandbox environments, ensure the user has a "Salesforce License" (not just a "Salesforce Platform" license) to avoid INVALID_GRANT errors ^[4].
• Diagnose SSO conflicts: If using single sign-on (SSO), verify the integration’s OAuth flow is compatible with the identity provider’s configuration, as mismatches can trigger OAUTHAPPROVALERROR_GENERIC ^[4].

For production vs. sandbox discrepancies, ensure the connected app’s "Start URL" points to the correct environment (e.g., https://login.salesforce.com for production or https://test.salesforce.com for sandbox) ^[4]. If errors persist, review the Salesforce login history for failed attempts, which may indicate blocked IP ranges or login hour restrictions.

API Limits, Rate Throttling, and Data Synchronization Errors

API governance and data synchronization issues frequently intersect, as exceeded limits (e.g., Bulk API quotas) halt syncs entirely, while field permission errors or malformed data trigger record-level failures. Salesforce enforces strict API limits—such as 15,000 API calls per 24-hour period for Enterprise Edition—with syncs pausing automatically at 80% quota usage in platforms like Crossbeam ^[6]. To mitigate this, administrators should:

• Monitor usage in real-time: Use Salesforce’s "API Usage" dashboard (under Setup > Monitoring > API Usage) to track consumption by integration ^[1].
• Adjust allocations: In HubSpot, navigate to Settings > Integrations > Salesforce > API Calls to reallocate calls between syncs and workflows ^[7].
• Implement retry logic: For temporary limits (e.g., REQUESTLIMITEXCEEDED), configure exponential backoff in custom integrations to auto-retry failed requests ^[1].

Data synchronization errors often stem from three core issues:

1. Field permission mismatches: - The integration user must have "Read" and "Edit" access to all synced fields in Salesforce. For example, HubSpot syncs fail if the user lacks permissions for custom fields like Account.CustomField_c ^[7]. - In Zendesk, verify the "Field-Level Security" settings for each mapped field in the Salesforce integration setup ^[3].
2. Malformed or missing data: - INVALID_FIELD errors occur when an integration references a non-existent field (e.g., Contact.InvalidField_c). Audit field mappings in the integration’s configuration panel ^[4]. - MALFORMED_ID errors indicate invalid record IDs (e.g., 15-character IDs instead of 18-character). Use Salesforce’s ID conversion tools to validate formats ^[4].
3. Record locking and dependencies: - Syncs may fail if parent records (e.g., Accounts) are locked during updates. Check Salesforce’s "Record Locking" logs under Setup > Monitoring ^[2]. - Circular dependencies (e.g., a Contact update triggering an Account update, which re-triggers the Contact) create infinite loops. Use middleware like APPSeCONNECT to map dependencies explicitly ^[2].

For bulk sync errors, platforms like HubSpot allow resyncing up to 100 records at once via the Sync Health tab, while larger batches require CSV imports with validated data ^[7]. In Intercom, sync triggers (e.g., attribute updates) can be adjusted to reduce frequency, as Salesforce checks for changes every 5 minutes by default ^[9].