Reopening issue that was closed by a bot.

Nextcloud allows characters in file and folder names that are illegal on some operating systems (windows).

Users in one of my installs use double quotes and colons. Nextcloud cannot open files or folder with symbols. Windows clients refuse to sync if there is a colon in the folder name.

My suggestion is to optionally not allow these special characters when creating files and folders in the web interface (or implement a setting where the administrator will specify an array of forbidden characters). Files and folders with these symbols in the sync folder must be renamed and the specified symbol removed before it can be distributed to other clients on different OSes.