Hi Isa,
Good day! Welcome to Q&A forum.
About the error message, this problem may be related to the user permission. However, you mentioned that the user has full control on the SharePoint site. You can let the user switch to different browsers/InPrivate window to see if the problem is related to the cache of the browser.
If the problem happens on all the browsers, you can let another admin to remove this user from the site first via site permission page and then re-add him to see the result.
If the problem persists, please check following tips to troubleshoot the issue:
- Check whether the folder/document has unique permissions, and the user has permission for the folder/document.
- Does the problem happen on other folders of the library on the same site? Let the user move a document into other folders or other document libraries, compare the results. 3.Try to remove the user and re-add the user into list permissions.
Hope these information helps.
Please do let us know if you have any further queries.
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