Previous documents

I have many documents that show up when I open your site but quite a few say this document does not exist but I can see it on my screen but it is too small to read and cannot open it. Is there any way to change that so I can see the documents?

You mean the Start Centre that you see on opening your installation of LibreOffice?

If you rename or move a document using your file manager then LibreOffice won’t know about the change and will still point to the old name/location. You can click the Open file icon to get a dialogue from which you can navigate to where you last renamed or saved your file. Or you could open your file manager, find the file(s) that you are looking for and double-click them to open; if you have merely moved the files then you could use your file manager’s search function to search for the file(s).

I can see the document on the page with my recent documents but it will say ERROR C:\Users\tomd0\OneDrive\Documents\Brue-12-16-22.odt does not exist so I can’t get to it or read it as it is too small. So not sure how what you said will help me get it
Tom

Check that your OneDrive settings aren’t making your documents online-only after 2 weeks.

You will need to ask on a Microsoft channel how to set up OneDrive to keep your files synchronised locally and online.

Note that this is a OneDrive problem, not LibreOffice

You see a small thumbnail, sometimes useful for recognizing a document, but not intended for reading. So forget about this for the moment.
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The main question is: Have YOU moved, renamed or deleted the document? The any solution depends on the things you did.
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Otherwise you have to find out where the document is. Two possibilities: Some security-system quarantained your file (not very likely for data-only files) or OneDrive is the culprit (as @EarnestAl already mentioned). There seems to be a setting where OneDrive has the files “only in cloud”, and this is said to be also true, if one tries to switch OneDrive off.
So maybe MS has moved your Data to the cloud. You should be able to find the data there, but that is outside of LibreOffice. Try to move your files back manually and change settings.
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I’m using Dropbox, but I would never sync my main folders. There is a subfolder only for the files I want to sync.

This Microsoft page might help, Save disk space with OneDrive Files On-Demand for Windows - Microsoft Support