Excel 2609 (Build 20430.20092) crashes when opening files from OneDrive – Rtc.dll 0xc0000005

Question

Excel 2609 (Build 20430.20092) crashes when opening files from OneDrive – Rtc.dll 0xc0000005

BAE DONGUK 10

After updating Microsoft 365 Apps for business to Version 2609 (Build 20430.20092), Excel crashes immediately when opening Excel files stored in OneDrive.

Environment

Microsoft 365 Apps for business
Excel Version 2609 (Build 20430.20092)
Current Channel
Windows
Files stored in OneDrive

Symptoms

Excel files opened directly from the OneDrive folder open briefly, then Excel immediately closes.
The same file works normally when copied to the local Desktop.
Other Excel files in the OneDrive folder show the same problem.

Event Viewer

Faulting application: EXCEL.EXE Version: 16.0.20430.20092

Faulting module: Rtc.dll Version: 16.0.20430.20092

Exception code: 0xc0000005 Fault offset: 0x000000000024177e

Troubleshooting already performed

Microsoft 365 repair
OneDrive reset
Unlinked and re-linked the OneDrive account
Disabled Excel add-ins
Rebooted Windows

None of these resolved the issue.

Important finding

I rolled Microsoft 365 back from Version 2609 (Build 20430.20092) to Version 2608 (Build 20326.20158).

The problem was immediately resolved.

Excel files stored in OneDrive now open normally with Version 2608.

This appears to be a regression in Excel Version 2609 related to opening OneDrive files, with the crash occurring in Rtc.dll.

Is this a known issue with Version 2609 / Build 20430.20092? Is there a fix planned for a newer build?After updating Microsoft 365 Apps for business to Version 2609 (Build 20430.20092), Excel crashes immediately when opening Excel files stored in OneDrive.

Environment

Microsoft 365 Apps for business
Excel Version 2609 (Build 20430.20092)
Current Channel
Windows
Files stored in OneDrive

Symptoms

Excel files opened directly from the OneDrive folder open briefly, then Excel immediately closes.
The same file works normally when copied to the local Desktop.
Other Excel files in the OneDrive folder show the same problem.

Event Viewer

Faulting application: EXCEL.EXE
Version: 16.0.20430.20092

Faulting module: Rtc.dll
Version: 16.0.20430.20092

Exception code: 0xc0000005
Fault offset: 0x000000000024177e

Troubleshooting already performed

Microsoft 365 repair
OneDrive reset
Unlinked and re-linked the OneDrive account
Disabled Excel add-ins
Rebooted Windows

None of these resolved the issue.

Important finding

I rolled Microsoft 365 back from Version 2609 (Build 20430.20092) to Version 2608 (Build 20326.20158).

The problem was immediately resolved.

Excel files stored in OneDrive now open normally with Version 2608.

This appears to be a regression in Excel Version 2609 related to opening OneDrive files, with the crash occurring in Rtc.dll.

Is this a known issue with Version 2609 / Build 20430.20092? Is there a fix planned for a newer build?

Ole Preben Vogler 0 Reputation points

2026-10-23T07:29:00.2733333+00:00

I have users running Microsoft® Excel® for Microsoft 365 MSO (Version 2609 Build 16.0.20430.20032) 64-bit with the exact same problem causing massive issues with KPI reports we need to deliver to customers.

3 answers

Your answer

Ole Preben Vogler 0 Reputation points

2026-10-23T07:29:00.2733333+00:00

I have users running Microsoft® Excel® for Microsoft 365 MSO (Version 2609 Build 16.0.20430.20032) 64-bit with the exact same problem causing massive issues with KPI reports we need to deliver to customers.

Answer 1

EmilyS_726 34,010 Volunteer Moderator

Microsoft released Version 2609, Build 20430.20182 on Oct 13th. Try updating to that. The issue could be addressed by this release.

Ole Preben Vogler 0 Reputation points

2026-10-23T07:58:39.68+00:00

We are running 2609, Build 20430.20180 and are faced with this issue.
EmilyS_726 34,010 Reputation points Volunteer Moderator

2026-10-23T13:01:22.4633333+00:00

I said Build 20430.20182, not Build 20430.20180.
Ole Preben Vogler 0 Reputation points

2026-10-27T09:01:35.5966667+00:00

Noted. Our clients are in Monthly Enterprise channel where this build level 20430.20182 is not available, but I will move 1 device to Current Channel and see if the issue is fixed. I see that Version 2609 is having build level 20430.20182 in Current Channel, but I also see that vers. 2610 20527.20088 is available here.
Ole Preben Vogler 0 Reputation points

2026-10-29T10:24:59.7266667+00:00

I moved 1 client to Current Channel and it's now updated to Version 2610 Build 16.0.20527.20112 (X64). The problem with corrupted Excel persists. I'm assuming this build level is accumulative so what's fixed in build level 20430.20182 also applies to the newer version.
EmilyS_726 34,010 Reputation points Volunteer Moderator

2026-10-29T13:05:23.93+00:00

Use answers to provide solutions to the user's question. I was hoping the Version 2609 (Build 20430.20182) would be worth a shot, as the release note says it resolved an issue that could cause Excel to close unexpectedly after coauthoring in a workbook.

In this case, it doesn't appear to be so. I would suggest testing version 2608 on one affected computer and see if it works. If so, I think this can be still a product regression issue

Answer 2

Killian N 4,490 Independent Advisor

Hi BAE DONGUK,

Your testing strongly suggests that the crash is build-specific rather than caused by the workbook, OneDrive synchronization, or an Excel add-in. In particular, the same cloud files work locally, and the problem disappears after reverting from Build 20430.20092 to Build 20326.20158.

The release notes for Build 20430.20092 mention a fix for Excel becoming unresponsive during closing, but they do not document a OneDrive opening crash or provide a planned fix build for this exception.

As an alternative to remaining on Version 2608, could you test whether temporarily disabling AutoSave prevents the crash:

Start Excel without opening a workbook.
Go to File > Options > Save.
Clear AutoSave OneDrive and SharePoint Online files by default in Excel.
Close Excel completely, reopen it, and test a OneDrive workbook.

This test is relevant because AutoSave and real-time co-authoring are activated for workbooks stored in OneDrive or SharePoint. Turning off AutoSave stops real-time synchronization, although the workbook must then be saved manually.

If Excel opens successfully with AutoSave disabled, that would further narrow the problem to the cloud collaboration or real-time synchronization path used by this build. It would provide a potentially less disruptive workaround than downgrading Office. However, it is only a diagnostic workaround, and users should save frequently because real-time co-authoring and automatic saving will be unavailable.

I would avoid manually deleting the OfficeFileCache folder as a general test. Please note that manually removing cache artifacts can itself cause Office documents to crash when opened from OneDrive or SharePoint and may create upload or recovery problems.

Since you are using Microsoft 365 Apps for business, the best next step is for your Microsoft 365 administrator to open a support request and include:

The Event Viewer entry and fault offset
EXCEL.EXE and Rtc.dll version 16.0.20430.20092
Confirmation that several OneDrive workbooks are affected
Confirmation that local copies open normally
Confirmation that Version 2608 resolves the crash
Whether disabling AutoSave changes the behavior

Office diagnostic logs can provide Microsoft with additional information about the processes and components involved in an application failure.

In the meantime, the safest practical options are to remain temporarily on Version 2608, test with AutoSave disabled, use Excel for the web, or work from a local copy while ensuring changes are synchronized carefully.

For reference

I hope the information I shared earlier was somewhat helpful in addressing your issue. If you have any further questions or updates, please don’t hesitate to share.

Kind regards,

Killian N 4,490 Reputation points Independent Advisor

2026-09-25T16:19:58.8733333+00:00

Hi BAE DONGUK,

Have you had a chance to review the information provided? Any updates would be greatly appreciated.
Eunsu Lim(임은수) 0 Reputation points

2026-09-28T06:30:26.1533333+00:00
I also experience the same symptoms.
I’m experiencing the same issue with the following versions:

EXCEL.EXE: 16.0.20430.20092

Rtc.dll: 16.0.20430.20092

The issue persists even with AutoSave turned off. I’ve tried all the troubleshooting steps mentioned above, but none have resolved it. However, the files open and work normally when moved from OneDrive to a local folder.
Killian N 4,490 Reputation points Independent Advisor

2026-09-28T16:27:50.7533333+00:00

Hi Eunsu Lim(임은수) ,

Thank you for testing this and reporting the result. Since the crash still occurs with AutoSave disabled, that workaround unfortunately does not address the underlying issue in your environment.

Could you check whether Event Viewer also shows the following fault offset: 0x000000000024177e

If it matches, please include it when reporting the problem through Excel > File > Feedback > Report a Problem or when opening a Microsoft 365 support request. This will help Microsoft correlate the reports using the same crash signature.

Until a corrected build is available, the remaining practical workarounds are using Excel for the web, working from a local copy, or temporarily returning to Version 2608 if your organization allows it.

Kind regards,
Eunsu Lim(임은수) 0 Reputation points

2026-09-28T23:43:56.59+00:00
Hello,

I am experiencing an issue with Microsoft Word when opening files from OneDrive.

The error information shown in Windows Event Viewer is as follows:

Application name: WINWORD.EXE, Version: 16.0.20430.20092

Faulting module name: Rtc.dll, Version: 16.0.20430.20092

Exception code: 0xc0000005

Fault offset: 0x000000000024177e

This issue occurs only when I open a file from OneDrive. I do not experience this issue when opening files stored locally on my computer.

I would appreciate it if you could investigate the cause of this issue and provide a solution as soon as possible.
BAE DONGUK 10 Reputation points

2026-09-29T03:06:06.56+00:00
Hi,

I experienced exactly the same issue after updating Microsoft 365 to Version 2609 (Build 20430.20092). Excel would crash immediately when opening files stored in OneDrive.

In my case, Event Viewer showed:

EXCEL.EXE: 16.0.20430.20092

Rtc.dll: 16.0.20430.20092

Exception code: 0xc0000005

Fault offset: 0x000000000024177e

I tried repairing Microsoft 365, resetting OneDrive, unlinking and relinking the OneDrive account, disabling Excel add-ins, and rebooting Windows, but none of these resolved the issue.

I eventually rolled Microsoft 365 back from Version 2609 to Version 2608 (Build 20326.20158), and the issue was immediately resolved. Excel files stored in OneDrive now open normally.

Temporary workaround: Roll back to Version 2608

If your organization allows Office version rollback, the following steps worked for me:

1. Close all Microsoft Office applications, including Excel, Word, Outlook, and PowerPoint.

2. Open Command Prompt (CMD) as Administrator.

3. Run the following command:

cd /d "%ProgramFiles%\Common Files\Microsoft Shared\ClickToRun"

4. Then run:

OfficeC2RClient.exe /update user updatetoversion=16.0.20326.20158

5. Wait for Microsoft 365 to complete the update/rollback process, then restart Windows.

6. Open Excel and go to File > Account to confirm that the installed version is now Version 2608 (Build 20326.20158).

After rolling back to this version, OneDrive Excel files opened normally on my PC.

If you are experiencing the same Rtc.dll crash on Build 20430.20092, rolling back to Version 2608 may be a useful temporary workaround until Microsoft releases a corrected build.

Since other users are now reporting the same Rtc.dll crash with the same exception code and fault offset, this increasingly appears to be related to Version 2609 rather than an individual PC or OneDrive configuration.

Note: This is only a temporary workaround. Office may automatically update to Version 2609 again, and organizations may manage Office updates through their IT policies. I recommend staying on Version 2608 only temporarily and updating again once Microsoft releases a build that fixes the issue.

Answer 3

Hi @BAE DONGUK

Based on the information provided, this appears to be a regression introduced in Excel Version 2609 (Build 20430.20092) rather than a local configuration issue.

The key indicator is that:

The crash occurs consistently when opening files from OneDrive.
The same files open successfully when copied to a local folder.
Standard remediation steps (Office repair, OneDrive reset, relinking the account, disabling add-ins, and rebooting) did not resolve the issue.
Rolling back from Version 2609 (Build 20430.20092) to Version 2608 (Build 20326.20158) immediately restored normal functionality.

The Event Viewer entry showing Rtc.dll as the faulting module with exception code 0xc0000005 further suggests that the failure is occurring within Office components included in that specific build.

At the time of writing, I am not aware of a publicly documented known issue specifically matching this exact scenario. However, the rollback test provides strong evidence of a build-specific regression.

I recommend:

Remaining on Version 2608 until a newer Current Channel build becomes available.
Monitoring the Microsoft 365 Apps release notes for fixes related to Excel, OneDrive integration, or application crashes.
Opening a support case with Microsoft and providing the Event Viewer logs and rollback results, as these details can help Microsoft confirm and investigate the regression.

If other users can reproduce the same behavior on Build 20430.20092, it would help determine whether this is a broader product issue rather than an isolated environment problem.

If this issue matches your experience, please consider upvoting this question. Additional votes can help increase visibility and assist Microsoft in determining the impact of the problem and prioritizing investigation.

**If you have encountered the same behavior, please share your Microsoft 365 Apps version, update channel, and any relevant Event Viewer details to help with troubleshooting and root cause analysis.**Based on the information provided, this appears to be a regression introduced in Excel Version 2609 (Build 20430.20092) rather than a local configuration issue.

The key indicator is that:

The crash occurs consistently when opening files from OneDrive.
The same files open successfully when copied to a local folder.
Standard remediation steps (Office repair, OneDrive reset, relinking the account, disabling add-ins, and rebooting) did not resolve the issue.
Rolling back from Version 2609 (Build 20430.20092) to Version 2608 (Build 20326.20158) immediately restored normal functionality.

The Event Viewer entry showing Rtc.dll as the faulting module with exception code 0xc0000005 further suggests that the failure is occurring within Office components included in that specific build.

At the time of writing, I am not aware of a publicly documented known issue specifically matching this exact scenario. However, the rollback test provides strong evidence of a build-specific regression.

I recommend:

Remaining on Version 2608 until a newer Current Channel build becomes available.
Monitoring the Microsoft 365 Apps release notes for fixes related to Excel, OneDrive integration, or application crashes.
Opening a support case with Microsoft and providing the Event Viewer logs and rollback results, as these details can help Microsoft confirm and investigate the regression.

If other users can reproduce the same behavior on Build 20430.20092, it would help determine whether this is a broader product issue rather than an isolated environment problem.

If this issue matches your experience, please consider upvoting this question. Additional votes can help increase visibility and assist Microsoft in determining the impact of the problem and prioritizing investigation.

If you have encountered the same behavior, please share your Microsoft 365 Apps version, update channel, and any relevant Event Viewer details to help with troubleshooting and root cause analysis.

Excel 2609 (Build 20430.20092) crashes when opening files from OneDrive – Rtc.dll 0xc0000005

3 answers

Temporary workaround: Roll back to Version 2608

Your answer