If you are getting an error message when opening an excel or word file in File Manager, it may be due to the file path being too long. Microsoft operating systems limit office files to 218 characters from the beginning of the path name to the end. When you open a remote file from File Manager, it is first downloaded to a cache folder. This will usually add about 60 characters to the path. Within File Manager, you need to shorten the names of the folders leading up to the file, or the file itself.
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