If the "Server Busy" message is blocking the desktop or an app and will not go away, the simplest supported step is to close the stuck app in Task Manager.
Important: any unsaved work in that app will be lost.
Steps:
- Press Ctrl + Shift + Esc to open Task Manager.
- In the list of apps, look for the app that appears stuck or is showing the message.
- Select that app.
- Select End task.
- Wait a moment. The app may not close instantly.
- Reopen the app if needed.
If the message appears when opening or saving only a few files, those files may contain links to data stored somewhere else. If that linked file was moved or deleted, the message can appear while Windows or Office tries to reach it.
If the message appears for many files, a slow or busy network connection can also cause it.
References: