this is a problem related to the fact that since you are modifying tags you are writing on fat32 filesystem. normally you should write on fat 32 partitions. check the /etc/fstab to see the write permissions. from what i know, i wrote on fat 32 only as root but maybe you can do this as a user(the user created in setup wizard). firstly, use 777 permissions for the directory where is mounted the fat32 partition. then, modify fstab like this with following options: defaults,umask=000 0 0. this allows every user to read and write.