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mustafaerdinc

macrumors newbie
Original poster
Sep 29, 2016
17
4
Hello,

After upgrading to macOS Sequoia on MBP 16 inch M2 MAX with 96 GB RAM, occasionally CPU and RAM is eaten by 10 to 20 process named and starting with WebThumbnailExtension waiting is not solving the issue, I need to open activity monitor and force quit. What is the reason behind this?

I have two studio displays attached to MBP in Clamshell mode with Apple Thunderbolt 4 cables.

Regards
 

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I’m experiencing the same issue on my Mac, and it's noticeably slowing things down. I also have to force quit the WebThumbnailExtension processes through Activity Monitor.
 
Apparently more people has this problem. I believe ther is a bug. Anyone has a solution?
 
I am also experiencing this issue. Anyone else running Microsoft Office, particularly OneNote, when it starts?
 
This is definitely is a Microsoft Office problem. Latest office update did not fix it. I believe the issue is related to cloud sync functions of Office.
 
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Anybody found a solution? I assume it's more of a spotlight issue, not related to office.
 
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One thing. I can't find many files when searching with spotlight even though they are on the drive.
 
I've been diving into the issue. It is really weird. I flushed the caches and changed the size of them (Cachelimits in the system settings) and killed the main WTE process (having 3500 threads). It appeared to be the Only way of getting things back to normal. Opening apps is not launching problem again however.

And I did update Chrome.
 
Last edited:
I made a script to alert if a new WebThumbnailExtension processes is created. .
This should tell user after doing "something" what causes the creation of new WebThumbnailExtension processes.

=> run it on script editor


set previous_pid to "" -- Initialize a variable to store the previous process ID

repeat
try
set current_pid to do shell script "pgrep WebThumbnailExtension"

-- Check if the process ID is new
if current_pid is not equal to previous_pid then
display dialog "WebThumbnailExtension is running with new PID: " & current_pid with title "Process Alert"
set previous_pid to current_pid -- Update previous process ID to the current one
end if

on error
-- If the process is not running, clear the stored process ID
set previous_pid to ""
end try

delay 5 -- Check every 5 seconds
end repeat
 
WebThumbnailExtension was not running on my Mac.
I started the app Microsoft OneDrive, which I’ve never used before. It had me log into Microsoft, give it a bunch of permissions, and WHAMMO!!! WebThumbnailExtension popped up in Activity Monitor.

So maybe check your Microsoft OneDrive folder and see how many files it contains. Or update your Office software to see if that clears the bug. Or stop using OneDrive.
 
WebThumbnailExtension was not running on my Mac.
I started the app Microsoft OneDrive, which I’ve never used before. It had me log into Microsoft, give it a bunch of permissions, and WHAMMO!!! WebThumbnailExtension popped up in Activity Monitor.

So maybe check your Microsoft OneDrive folder and see how many files it contains. Or update your Office software to see if that clears the bug. Or stop using OneDrive.
Great info. I also updated M$ apps.

At the monent I have no problems with the WTE. However I found the SSD access (like to save a file from any app is slow to open folders).

I have to restart once jobs are done for today and see if the problems vanish/reappear.
 
Guilty one is most likely OfficeThumbnailExtension..

(/System/Library/ExtensionKit/Extensions/OfficeThumbnailExtension.appex/Contents/MacOS/OfficeThumbnailExtension)


Näyttökuva 2024-11-18 kello 14.07.51.png



Open files

/
/System/Library/ExtensionKit/Extensions/OfficeThumbnailExtension.appex/Contents/MacOS/OfficeThumbnailExtension
/Library/Preferences/Logging/.plist-cache.TFk0LPa3
/System/Library/CoreServices/SystemVersion.bundle/English.lproj/SystemVersion.strings
/System/Library/Fonts/Helvetica.ttc
/System/Library/Fonts/Supplemental/Arial.ttf
/System/Library/Fonts/Supplemental/Arial Bold.ttf
/System/Library/Fonts/Supplemental/Times New Roman.ttf
/System/Library/Fonts/Supplemental/Times New Roman Italic.ttf
/private/var/folders/zd/tw6v9qbx1q582b9cq10pt2_c0000gn/0/com.apple.LaunchServices.dv/com.apple.LaunchServices-6014-v2(4afb808~).csstore
/System/Library/Fonts/Supplemental/Times New Roman Bold.ttf
/System/Library/Fonts/Supplemental/Times New Roman Bold Italic.ttf
/System/Library/Fonts/Supplemental/Arial Italic.ttf
/System/Library/Fonts/HelveticaNeue.ttc
/usr/share/icu/icudt74l.dat
/private/var/folders/zd/tw6v9qbx1q582b9cq10pt2_c0000gn/0/com.apple.LaunchServices.dv/com.apple.LaunchServices-6014-v2.csstore
/dev/null
/dev/null
/dev/null
/System/Library/PrivateFrameworks/OfficeImport.framework/Versions/A/Resources/OAShapeTypes.zip
/System/Library/PrivateFrameworks/OfficeImport.framework/Versions/A/Resources/DefaultTableStyles.zip
 
Great info. I also updated M$ apps.

At the monent I have no problems with the WTE. However I found the SSD access (like to save a file from any app is slow to open folders).

I have to restart once jobs are done for today and see if the problems vanish/reappear.
I removed OneDrive and then I removed every trace of OneDrive.
While I was at it, I removed every trace of Adobe, which is a heck of a chore! I had the usual Photoshop/Lightroom license for years, but I canceled my license and uninstalled them... but MAN, Adobe files are like locusts.
 
It’s definitely a bad marriage between Sequoia and Excel. While all the other MSOffice applications works properly, whenever I Oper Excel and click “save” (or excel save automatically) the WTE file open up and spread! The so-called “level 2” of Apple “Specialists” have no idea: they adviced me to 1. Format the Mac, 2. Change my apple account, 3. Buy a new computer (and I bought new iMac and new MacBook Pro as I need to work), …the last Specialist told me “I will forward your trouble to Cupertino specialists”(!!!)…the only way I personally found thanks to your idea is simply not to use Excel…
 
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It’s definitely a bad marriage between Sequoia and Excel. While all the other MSOffice applications works properly, whenever I Oper Excel and click “save” (or excel save automatically) the WTE file open up and spread! The so-called “level 2” of Apple “Specialists” have no idea: they adviced me to 1. Format the Mac, 2. Change my apple account, 3. Buy a new computer (and I bought new iMac and new MacBook Pro as I need to work), …the last Specialist told me “I will forward your trouble to Cupertino specialists”(!!!)…the only way I personally found thanks to your idea is simply not to use Excel…
It’s a bug in Microsoft OneDrive.
 
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