Problem description

• Files cannot be displayed / opened / edited / deleted.

• Files in ONLYOFFICE appear empty.

• PDF files cannot be displayed in the preview.

• Folder contents are not visible.

• Uploaded documents cannot be displayed.

Analysis

Do the file or folder names contain an umlaut character (ä / ö / ü)? This may be a combining character.

Technical background

An encoding problem is present: The special character in the file name is problematic, so that the corresponding file on the storage system cannot be assigned. Although the file has been uploaded to the server, it cannot be displayed/edited/deleted. A “combining character” is a string of two characters with which the umlaut character can be formed, see:

• https://en.wikipedia.org/wiki/List_of_Unicode_characters#Combining_marks
  https://en.wikipedia.org/wiki/Combining_character

When renaming, it can be seen that two keystrokes are required when deleting a combining character, as the character is a string of two characters.

Additional technical information: On MacOS systems, the combining umlaut characters can be generated instead of UTF-8-encoded umlaut characters. These strings, e.g. the small “ü” with chr(117) + chr(776), can also be generated artificially with programming languages such as Python3. The LRZ storage system, which currently uses NFSv3, does not intervene here and tolerates/preserves these strings. However, the LRZ Sync+Share software expects an UTF-8 encoded character, but cannot find the correct file on the storage system.

Solution

Please rename the file(s) or the subfolder with umlaut characters in the LRZ Sync+Share web interface (accessible at https://syncandshare.lrz.de).