As @PiotrP.Karwasz says no write permission for the group.
Solutions (one of):
- give write permission to the group:
chmod g+w -R /path/to/folder - give write permission to the user: as you did, but don't switch it back.
- give write permission to (possibly many) additional users/groups: using
setfaclsee What are the different ways to set file permissions, etc., on GNU/Linux?