Why Your SFMC Automation Stopped Working (And How to Fix It Fast)
Few things derail a marketing team’s day quite like discovering that an SFMC automation stopped working overnight. Emails didn’t send, data extensions weren’t updated, and your carefully orchestrated campaign is sitting idle. If you’re staring at a paused or errored automation in Salesforce Marketing Cloud right now, you’re not alone — this is one of the most common (and most frustrating) issues SFMC administrators face. The good news: most automation failures have predictable causes and straightforward fixes.
In this post, we’ll walk through the most frequent reasons automations break in Marketing Cloud, how to diagnose the root cause quickly, and what you can do to prevent these failures from happening again.
The Most Common Reasons SFMC Automations Fail
1. Data Extension Schema Changes
This is the number-one culprit behind automation failures. If someone modifies a data extension that your automation depends on — adding a column, removing a field, or changing a data type — the automation’s SQL query or import activity can break silently. SFMC won’t always warn you in advance; it simply fails at runtime.
What to check: Open the Activity tab of your automation and look at which step errored. If it’s an SQL Query or Import File activity, compare the target data extension’s current schema against what your query or file expects. Even a single renamed column can cause a complete failure.
2. Expired or Revoked API Credentials
Automations that rely on external data sources, SFTP file imports, or API-triggered sends will fail if the underlying credentials have expired. This is especially common with installed packages whose OAuth tokens have a set lifespan, or when someone rotates SFTP passwords without updating the corresponding File Transfer activity.
What to check: Navigate to Setup > Installed Packages and verify that your server-to-server integrations are still active. For SFTP-based imports, confirm the credentials in your File Transfer activity match the current SFTP account details under Administration > Data Management > File Locations.
3. SQL Query Timeouts
Salesforce Marketing Cloud enforces a 30-minute timeout on SQL query activities. If your data extensions have grown significantly or your query involves multiple complex joins without proper filtering, the query may simply run out of time. The automation will report an error, but the error message (“Query failed”) is often unhelpfully vague.
What to check: Run your SQL query manually in Query Studio and observe the execution time. If it’s approaching the 30-minute mark, you’ll need to optimize — add WHERE clauses to limit row counts, break the query into smaller steps, or use indexed fields in your JOIN conditions.
4. Send Classification or Delivery Profile Issues
If your automation includes an email send activity, it can fail due to problems with the send classification, sender profile, or delivery profile. This often happens after org-wide changes — for example, if a shared sender profile’s “From” address is modified or a CAN-SPAM compliance footer is removed from a delivery profile.
What to check: Open the email send activity and verify each component: the send classification, sender profile, and delivery profile. Make sure the “From” email address is verified and that the physical mailing address in the delivery profile is populated.
5. Business Unit Permission Conflicts
In multi-business-unit SFMC environments, automations can fail when shared data extensions or shared content lose their sharing permissions. If an admin changes sharing rules at the enterprise level, an automation in a child business unit may suddenly lose access to a data extension it was reading from or writing to.
What to check: Confirm that all data extensions referenced in your automation are still shared to the business unit where the automation runs. Check under Shared Items in the parent business unit’s data extension folder.
6. Schedule Conflicts and Overlapping Runs
SFMC does not allow an automation to start a new run while a previous run is still executing. If your automation takes longer than expected (due to growing data volumes) and the next scheduled run attempts to start, the new run will be skipped. Over time this can cascade into what appears to be a “stopped” automation even though its status still shows as Active.
What to check: Review the automation’s run history in Automation Studio. Look for overlapping timestamps or “Skipped” entries. If runs are consistently taking longer than the interval between scheduled starts, you’ll need to either optimize the automation’s activities or increase the time between runs.
How to Diagnose the Problem Quickly
When an automation fails, follow this triage checklist:
- Check the Run History: In Automation Studio, click on the automation and review the Activity tab. The step that failed will be highlighted in red. Note the exact error message and timestamp.
- Examine the Error Log: For SQL queries, the error message usually indicates what went wrong (invalid column name, timeout, etc.). For imports, look for file-not-found or schema mismatch errors.
- Test Each Step Manually: Run the failed activity in isolation. If it’s a SQL query, execute it in Query Studio. If it’s a file import, manually check the SFTP location for the expected file.
- Review Recent Changes: Ask your team: did anyone modify a data extension, update credentials, change sharing rules, or deploy new content in the last 24-48 hours? Automation failures almost always correlate with a recent change.
- Check SFMC System Status: Occasionally, the problem is on Salesforce’s end. Check trust.salesforce.com for any ongoing incidents affecting Marketing Cloud.
Preventing Automation Failures Before They Happen
The best fix is the one you never need. Here’s how experienced SFMC administrators keep their automations running reliably:
- Implement proactive monitoring. Don’t wait for a stakeholder to notice that an email didn’t send. Use a monitoring solution like Martech Monitoring to get real-time alerts when automations fail, skip, or run longer than expected. Catching failures within minutes — rather than hours or days — drastically reduces the impact on your campaigns.
- Document your data extension dependencies. Maintain a simple map of which automations read from and write to which data extensions. When someone needs to change a schema, they can check the map first and update dependent queries before they break.
- Set up error-handling automations. Create a “watchdog” automation that checks whether critical data extensions were updated within their expected timeframes. If a key DE hasn’t been refreshed by 8 AM, the watchdog can send an alert email to your ops team.
- Rotate credentials on a schedule. Don’t wait for API keys or SFTP passwords to expire unexpectedly. Set calendar reminders to rotate them proactively and update all dependent automations at the same time.
- Optimize SQL queries as data grows. Review your query execution times quarterly. What ran fine on 500,000 rows may time out on 5 million. Add indexes, tighten WHERE clauses, and consider breaking monolithic queries into staged steps.
- Use naming conventions and folder structures. Clearly name your automations, queries, and data extensions so that anyone on the team can understand what depends on what. Sloppy naming leads to accidental modifications and broken dependencies.
When to Escalate to Salesforce Support
If you’ve exhausted the troubleshooting steps above and your automation is still failing with vague or inconsistent error messages, it may be time to open a case with Salesforce Support. Provide them with:
- The automation name and MID (Member ID) of the business unit
- The exact error message and timestamps from the run history
- A description of what changed before the failure started
- Confirmation that you’ve tested each step in isolation
Salesforce support can access server-side logs that aren’t visible in the Automation Studio UI, which can reveal underlying platform issues.
Don’t Let Broken Automations Derail Your Campaigns
SFMC automation failures are inevitable — but slow detection isn’t. The teams that recover fastest are the ones who know about failures before anyone else does. If you’re tired of discovering broken automations hours (or days) after the fact, try Martech Monitoring free and get instant alerts the moment something goes wrong in your Marketing Cloud account. Your future self — and your campaign stakeholders — will thank you.
Take Action on Your SFMC Monitoring
Download the free SFMC Monitoring Checklist — 27 critical items to monitor, with recommended frequencies and alert thresholds for each.
Or watch the product demo to see how Martech Monitoring automates all of this for you — catching Journey failures, Automation errors, and Data Extension issues in minutes, not days.
Start monitoring free — no credit card required.