
Hi @Ahmed Yehia,
Thank you for posting in this community.
Since we can't reproduce your situation, we need to narrow down the problem and try some things.
1.Please open IIS ->find your web application pool->restarted it.
2.Are other users facing the same problem? View through another computer or account.
3.Check if the same issue occurs with other SharePoint site collections.
4.You could try to clear browser cache then restart it.
5.Try to use a different browser or your browser's InPrivate mode to see if the same error occurs.
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