Fix Excel RunAs Error 1312: Logon Session Does Not Exist
Question details
The user needs to start Excel as another Windows user without receiving error 1312.
- Product
- Microsoft Excel
- Device & OS
- Windows
- Scenario
- Excel is launched with RunAs under a different Windows user account.
- Observed behavior
- Recent Office builds report that the specified logon session does not exist or may have been terminated, while an earlier build worked.
Open Excel normally and check File > Account > Product Information for the Office version, build, and update channel. Have the RunAs command and the affected account name available for testing.
Update Office and retest Excel RunAs
Check whether a newer Office build resolves the error before considering a rollback.
In Excel, select File > Account and note the version, build number, and update channel under Product Information.
On the same Account page, select Update Options > Update Now. If updates are managed by your organization or the option is unavailable, contact your IT administrator.
Open Command Prompt and run the same RunAs command that previously failed, then check whether Excel starts under the intended account.
Compare RunAs behavior across Office apps
Gather details that can help distinguish an Excel-specific issue from a broader Office or account issue.
Consider an Office build rollback with IT
Use this option when the error began after an Office update and persists on the latest available build.
Open Excel Workbooks with WPS Spreadsheet
WPS Office is a free, lightweight alternative with a familiar spreadsheet interface. Its Excel format compatibility makes it easy to move existing workbooks, although it does not fix Microsoft Excel's RunAs error.
Frequently Asked Questions
Where can I find my Excel build number?
Open Excel and select File > Account. Look under Product Information for the Office version, build, and update channel.
Does Run as administrator do the same thing as RunAs another user?
No. Run as administrator requests elevated permissions, while RunAs starts a program under a specified account. Testing both can help narrow down the issue.
Will updating Office always fix error 1312?
No. Select File > Account > Update Options > Update Now to test the latest available build, but the reported error persisted after one update.
Which Office build worked in the reported case?
The user reported that rolling back to version 2004, build 12730.20352, restored RunAs functionality. Consult your administrator before using an older build because it may be unsupported or missing security fixes.
