Microsoft Excel 365 HUGE Memory Leak (50 GB RAM)

Copper Contributor



I read this article yesterday and I was wondering if you could take a look at a very tiny program I created in Microsoft Excel. I can email you the Excel file if you are interested. 

Annotation 2022-08-22 163028.jpg

This program has an overwhelming SUPER SPEED MEMORY LEAK (from 200MB to 50GB in seconds!). I also created a 2 min. video. It crashes Windows 10 in seconds.


I have already created another Excel version (3.1 MB) that prevents this error but I am really curious to know your insights.


Program/Environment characteristics:

  • 3 sheets: catalogs, transactions, report
  • 4 tables: 3 catalogs ( 5 – 100 rows) + 1 transactional (60,000 rows)
  • 3 Pivot Tables
  • 2 Pivot Charts
  • Very simple VBA
  • Data Model with 3 tables.
  • 6.0 MB file size
  • Microsoft® Excel® for Microsoft 365 MSO (Version 2207 Build 16.0.15427.20182) 64-bit
  • Windows 10 Version 21H1 (OS BUILD 19043.1889)

Problem occurs after hitting the Refresh button and then changing to the transactions sheet (60, 000) rows. Then RAM consumptions hits.


My guess is that a combination of:

  • Application Screen Updating
  • Freeze Panes
  • 4K Monitor
  • 60K data rows
  • Data Model refresh??
  • Calculated columns??

causes this error.

Have you ever experienced a similar behavior?



36 Replies

@ExcelClaro I've been observing the same behavior for a while on files simpler than what you describe. In addition to the sudden memory spike, the video freezes. One of the triggers seems to be switching tabs -- perhaps while a previously invoked operation hasn't finished. However, other triggers exist that I haven't been able to identify. Fortunately, saving is possible, and I'm able to close Excel by clicking the X in the upper right of the window. However, the problem is annoying. A fix would be great.


Here's my setup:


OS: Win 10 21H2 Build 19044.1889

Processor: Intel(R) Core(TM) i9-9980XE CPU @ 3.00GHz 3.00 GHz (18 physical cores)

RAM: 128 GB

Video Card: NVIDIA GeForce RTX 2080 Ti running 3 4k displays via Display Port

Excel 365 Version: 2207 Build 15427.20210


@NeedMoreRAM Thanks for your reply!

Yes, same symptoms here: video freezes and Windows crashes eventually if the Excel file is NOT closed immediately. I think it has to do with the freeze panesswitching among sheets, *4K display* and MAYBE thousands of records. By curiosity, this error does NOT come out when using one of my lateral monitors which are Full HD, not 4K. 

Really annoying! :grimacing_face:

Here is my setup:


  • DELL Precison T5820 Workstation
  • Intel Xeon(R) W-2145 @ 3.7GHz 8 Cores / 16 Threads
  • 64GB RAM DDR4 @ 2666 MHz
  • Western Digital Black 500GB SN750 NVMe™ SSD 3,100MB/s read 1,600MB/s write
  • NVIDIA Quadro M2000, 4GB GDDR5, 75W, 106GB/s, PCIe 3.0 x16, 4x DPs
  • 1x BENQ PD3200U 32" 4K Ultra HD LCD Display Port
  • 2x DELL P2719H LED 27'', Full HD, Widescreen, DisplayPort


EDIT: 2022/SEP/14

I have attached some pictures using Sysinternals Process Explorer and DLL Export Viewer. Somehow this library Mso40UIwin32client.dll has something to do with this error. It exposes these 4 functions:


MsoDoFontLinkRgwch 0x000000018026c530 0x0026c530 485 (0x1e5) Mso40UIwin32client.dll C:\Program Files\Microsoft Office\root\vfs\ProgramFilesCommonX64\Microsoft Shared\OFFICE16\Mso40UIwin32client.dll Exported Function

MsoPwlfFromFlinfo 0x000000018030b1b0 0x0030b1b0 1150 (0x47e) Mso40UIwin32client.dll C:\Program Files\Microsoft Office\root\vfs\ProgramFilesCommonX64\Microsoft Shared\OFFICE16\Mso40UIwin32client.dll Exported Function


MsoCrCbvGet 0x00000001801ee190 0x001ee190 1933 (0x78d) Mso40UIwin32client.dll C:\Program Files\Microsoft Office\root\vfs\ProgramFilesCommonX64\Microsoft Shared\OFFICE16\Mso40UIwin32client.dll Exported Function


MsoFreeFlinfo 0x000000018030b970 0x0030b970 2751 (0xabf) Mso40UIwin32client.dll C:\Program Files\Microsoft Office\root\vfs\ProgramFilesCommonX64\Microsoft Shared\OFFICE16\Mso40UIwin32client.dll Exported Function


@ExcelClaro I'll start documenting specifics here whenever I observe this phenomenon. One other note for now is that I've had instances where RAM usage has spiked to 80GB-90GB before returning back to the normal range for the file I'm using (generally 200MB-500MB). In those cases, video begins updating normally, and I can work with the file again -- even though subsequent memory spikes seem to happen more frequently. In other instances, the RAM usage goes past 90GB, but I've always closed Excel before reaching my system limit.


Same here...

My PC:  AMD 5900X + 64GB + RTX3080Ti + 3440x1440x60Hz + Windows 10 Pro + Excel 365

If Excel works normally, it consumes 150-500MB of RAM. When it starts to lag, it consumes 40+GB. Usually the image freezes for a while and the only solution is to save the sheet and reopen Excel.


For me, the problem has been present at least from June 2022... I tried to solve the problem with a clean installation of Windows 10, then Windows 11 (no comment), drivers update or outdate... then I screamed at my PC and threatened him with a hammer... ;)


I noticed that there is no problem if:
- using Excel 2010
- using Excel 365 with "Hardware Acceleration" disabled
(this option has been removed some time ago - big "thanks" to Microsoft)



Thanks for your reply! It was fun to read. :beaming_face_with_smiling_eyes: I can feel your frustration. :\

Yes, the very same symptoms are there: specially the 4K monitor. I think that's the main variable suspect.

Hope Microsoft gets it fixed ASAP. 🙏🏻

@ExcelClaro Mine spikes memory leaks, then my CPU usage goes to 79% of just System Interrupts and locks up until I can get enough CPU free to kill the process, then reboot.  Only Excel seems to cause this.  Seriously needs a fix.

@ExcelClaro I’ve had this issue for a few months. It occurred after a standard windows and/or computer update. I didn’t take note at the time which update. I’ve only had issues with Excel no other programs.


I went through the standard options of clearing the roaming files, running XLStyles to clean the workbook, running in safe mode, updating windows, office, computer etc., uninstalling and reinstalling office, uninstalling and reinstalling office with support and recovery assistant, running the system file checker to repair files etc. None of these helped.


I noticed this error occurred when moving within a sheet or between sheets. It was not workbook dependent as it happened with different files some complex with macros, some simple without macros, some new, some old. All of those files worked without issue on different computers I also use (both cheaper laptops running windows 10 and both using 4K external monitor). It never occurred when idle, only when moving within a workbook.


In running Windows Event Viewer I discovered a Windows Hardware Error Architecture (WHEA) event with the PCI express root port every few seconds. This was caused by the Link State Power Management setting for PCI Express. Turning this off (from the default power saving mode) fixed the WHEA issue and after making this change I was trouble free for a couple of weeks. In the last two days I've had the issue again on a couple of occasions. Beforehand it was a continuous problem happening multiples time per hour.  


Computer: Alienware Aurora R12, Windows 11, Office 365, 64Gb RAM, i7-11700k, Nvidia GeForce RTX3070, Samsung 4K

@Id_rather_ride I have no WHEA errors. You should search for new drivers or BIOS on Dell website.


I'm testing new drivers (chipset AMD X570 + nVidia), but no luck.


Also I discovered there is an optional update KB5017380:

"Fixed an issue that occasionally causes explorer.exe to stop working when explorer.exe opens"



@tomoam2 thanks for the reply. I've run all windows updates, updated all drivers etc. on the system. The WHEA errors disappeared once the Windows power setting for the PCI was changed. Today I set the display graphics for excel to high performance, no issues since but it's really just grabbing for straws at this point. Mine issue quite specific to the one machine, I've had no issues on two other laptops.

@tomoam2 My Excel lockup is also on an AMD/nVidia laptop.  Lenovo Legion 5 Pro, AMD 5800H + nVidia 3070.

@Clifton_Cline Hi again (everybody),

Did you try this one:
"Assign application to specific GPU

To make Outlook to use a specific graphics card (i.e. use a basic driver so it disables hardware acceleration).

  1. Open Graphics Settings

    • Windows 11
      Start> Settings> System> Display> (section) Related Settings> Graphics

    • Windows 10
      Start> Settings> System> Display> (section) Multiple displays> Graphics settings

  2. Select: Desktop app

  3. Use the Browse button to add Outlook.exe (you can use Process Explorer to find the path if it is running or right click on the shortcut and go to properties.)

  4. After you’ve added Outlook, select it from the list and press the Options button to select your GPU.

  5. Use the Power Saving GPU: Microsoft Basic Render Driver to turn off hardware acceleration like you used to be able to do an easier way."

Excel 365 works much worse than the 2010 version, but maybe this method will speed it up until the patch is released?


I don't understand why Microsoft can't just restore the Disable Hardware Acceleration option?!


Yes the registry is set to 1.
I had set the card to High Performance for the Excel app. It crashed again this morning so I'll try the Power Saving mode now.
I was at Power Saving Mode... no luck, at High Performance is a little better (little = little little better)...
I'm tired of this problem with Excel 365. Tech support asked me to register the problem using "icesdptool". Ofc my antivirus is blocking this tool and it is not easy to use. Thank God I have 25 years of experience in operating and servicing computers.

Have any of you tried to disable Nvidia Share in Geforce Experience?

@tomoam2 Looks like the UX is slightly modified for GeForce Experience. The equivalent toggle now appears to be called In-Game Overlay. I haven't experimented with it. If this ends up being a source of the problem, it's weak that Excel 365 has issues when I run lots of other apps that don't have such issues.


I've triggered the memory leak one or two times since my last activity here, but I don't have anything intelligent to add regarding possible causes. I wish I could reproduce the issue reliably. Since you have Tech Support's ear, I'll reach out to them as well. 

My experience with tech support was unfruitful. @tomoam2, it sounds like you got further with tech support than I did. However, I'm going to try escalating by reporting the bug via Excel -> Help -> Feedback.
No luck with this change for me

I'm testing new solution:

1. Download and install Microsoft Support and Recovery Assistant for Office 365 -
2. Use SaRA to uninstall Office 365.
3. Use "regedit" to delete HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office
4. Reboot your PC and install Office 365 (I used my OfficeSetup.exe from July 2022)
5. Check for updates in Excel (File > Account > ... )

It's too early to celebrate, but ...
I've uninstalled and reinstalled a few times with sara. It was always better for a while afterward but the issue still came back. I think I did the regedit at some point as well but I'm not 100% on that. I was about to do this again so I'll make sure to add the regedit step and see how it goes.