There are several file types and keywords which are restricted on SharePoint online. Even if you are migrating content from any external source using SharePoint Migration Tool available for SharePoint Online or through any 3rd party migration tool on OneDrive or SharePoint Online document library,
I am sharing the list of all those Invalid characters, file names, types which are restricted on SharePoint Online and OneDrive for business.
| Restrictions | Details |
| Invalid characters | If a file or folder contains any of the characters listed below, it may prevent files and folders from syncing. Rename the file or folder to remove these characters before you upload it: “ * : < > ? / \ | |
| Invalid file or folder names | These names aren’t allowed for files or folders: . lock, CON, PRN, AUX, NUL, COM1 – COM9, LPT1 – LPT9, vti, desktop.ini, any filename starting with ~$. |
| Invalid or Restricted file types | Microsoft recently removed the restriction on file types and now the invalid ore restricted file types can be uploaded to SharePoint Online document library Sync client using OneDrive sync client or any migration tool. These file types will not work until unless custom scripting is enabled on the site collection. .aspx, .asmx, .ascx, .master, .xap, .swf, .jar, .xsf, .htc |
| Network or mapped drives | You can’t add a network or mapped drive as your OneDrive sync location. OneDrive doesn’t support symbolic links where the Link and Target are both located in the same library location. |
| Elevated privileges | OneDrive can’t be run with elevated privileges. |
| Shared with Me | You can’t synchronize the Shared with Me view grouping of files from a OneDrive for Business site. |
