
Hi @HD ,
Currently there is no news that sharepoint Office on the Web service will stop service. In my sharepoint online test environment, I can open documents directly in the browser.
1.Try changing the default opening method: open in the browser
Library Setting->Advanced settings->Open in the browser
2.Try to clear browser cache then restart it.
3.Try to use a different browser to see if the same error occurs.
4.Check if the same issue occurs with other SharePoint site collections.
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