Webthumbnailextension high memory and CPU usage

macdaddy709875 wrote:

Since updating to Sequoia last October, my Mac Studio with 32gb of Ram becomes unusable for workflow due to multiple instances of Webthumbnailextension averaging 775mb each as described in Activity Monitor. This also happens on my MacBook Air M2 with 8gb of Ram. These files do not clear on their own and must be force-quit in Activity Monitor to free up enough Ram and lower CPU usage enough to continue working. I've scoured the web and found no solutions that stop this from recurring. Opening MS Excel documents and switching back and forth with other software seems to trigger it. All Sequoia updates have been installed and I upgraded MS Office to the latest version with all updates installed. The only thing that helped at all was turning off Show Icons, Show Icon Preview, and Show Preview Column in Finder, but this only reduced the number of Webthumbnailextension files that are generated. Any help or suggestions would be appreciated. It's driving me crazy and ruining my trust in Apple.

see if there is anything here—

WebThumbnailExtension consuming all CPU c… - Apple Community

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The current stable release of Sequoia including bug fixes, security updates is macOS 15.3.1

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