Excel for Mac crashes (EXC_BAD_ACCESS, reproducible) on Refresh All of 14 Power Queries from OneDrive, started after macOS 26.7.2 update

Create a local copy outside the OneDrive-synced folder and run Data → Refresh All there; this is the fastest remaining test to distinguish a OneDrive/file-location interaction from an Excel Refresh All defect.

1. Isolate the file location

1. Quit Excel and wait for OneDrive to report that syncing is complete.
2. In Finder, copy the workbook and all source files into a new local folder that is not managed by OneDrive, such as a folder under Downloads.
3. Open the copied workbook.
4. If its Power Query sources use absolute paths, update them to the copied local files.
5. Select Data → Refresh All.

Microsoft’s Excel crash guidance specifically recommends moving a file locally to determine whether the problem is associated with the workbook or where it is stored.^1^

Interpret the result as follows:

• Local copy succeeds: the scope includes OneDrive synchronization or the synced paths. Keep the reporting workbook and inputs local during refresh, then copy the completed workbook back to OneDrive after Excel closes.
• Local copy still crashes: the failure is in Excel’s combined refresh path or workbook-level state, rather than basic access to the individual source files.

Because individual refreshes already succeed, there is no value in repeating update checks, restarting, or changing background-refresh settings.

2. If the local copy still crashes

Test a duplicate, not the production workbook:

1. Create a duplicate of the local workbook.
2. In Data → Queries & Connections, review both queries and connections for obsolete or duplicate items.
3. Also inspect workbook links and defined names for stale external references.
4. Remove only confirmed-unused entries from the duplicate, then retest Refresh All.

Refresh All can process more workbook-level objects than the 14 visible query refreshes, including stored connections and other refreshable metadata. A similar Refresh All case was resolved by inspecting queries, connections, workbook links, defined names, and cached metadata.^2^

If nothing obsolete exists, use copies of the workbook to isolate whether the crash depends on concurrency or one query combination:

1. Keep seven queries in one test copy and the other seven in another.
2. Run Refresh All in each.
3. Continue halving the crashing set until the smallest crashing combination is identified.

Do not treat a query as defective merely because it belongs to the failing combination. Power Query can issue additional requests during privacy evaluation, preview/background analysis, and other engine tasks, so Refresh All is not necessarily equivalent to 14 simple sequential refreshes.^3^

3. Operational workaround

Continue refreshing the queries individually and save the workbook after completion. That is the lowest-risk workaround because it is already successful in this environment.

Do not disable the Power Query privacy firewall merely as a crash workaround. Microsoft documents that doing so can reduce duplicate privacy-analysis requests, but it should be considered only when disclosure between the involved data sources is acceptable.^3^

4. Escalate this as a reproducible Excel crash

Microsoft’s current Excel for Mac known-issues page does not list this exact Refresh All / Power Query / EXC_BAD_ACCESS failure.^4^ Submit it through Excel → Help → Feedback, enable contact permission, and attach the crash report; this route sends the report to the applicable product team.^5^

For the business-impacting case, have the Microsoft 365 tenant administrator open a support ticket and include:

• Excel version and full build
• macOS version and build
• Apple Silicon model
• both crash timestamps
• both StackHash values
• exception and fault address
• identical Microsoft Excel module offset
• confirmation that individual refresh succeeds
• result of the local-copy test
• smallest query combination that reproduces it, if isolated
• sanitized workbook and sample source files, if organizational policy permits

Redact source paths, credentials, query expressions, endpoint details, and business data before posting diagnostics publicly. Microsoft notes that refresh diagnostics can contain query and endpoint information.^6^

Avoid a full Office uninstall unless Microsoft Support requests it or the crash also occurs in unrelated workbooks. The deterministic Refresh All trigger and successful individual refreshes make a targeted workbook/location test more informative than reinstalling first.

References

1. Excel not responding, hangs, freezes or stops working
2. Pivot table linking to non-existent data source - Microsoft Q&A
3. Why does my query run multiple times?
4. Fixes or workarounds for recent issues in Excel for Mac | Microsoft Support
5. How do I give feedback on Microsoft 365? | Microsoft Support
6. Understand Dataflow Gen2 detailed refresh logs