Hi @Syed Shah ,
Welcome to our forum!
What's the version of your Outlook client? (File>Office Account>About Outlook) Please make sure you have upgraded your Outlook and Windows to the latest version.
And does this issue occur recently? If so, have you done any specific operations before that? Such as installing some programs and running some scripts? Considering the impact of some third-party programs on your computer, please try to perform a clean boot for windows and check if the issue still occurs.
In addition, i found that some user mentioned that the issue may be resolved by command: outlook.exe /cleanviews. Just try the following to check if the issue persists: Start > Run > outlook.exe /cleanviews.
Hope to help you!
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