Ubuntu 13.04 apt-get error : Too many levels of symbolic links

# tail -1 /etc/lsb-release ;uname -ri DISTRIB_DESCRIPTION="Ubuntu 13.04" 3.8.0-33-generic x86_64

When issuing apt-get upgrade, I saw the following errors.

I am not sure what is the trigger on this issue, because other Ubuntu13.04 boxes can do apt-get upgrade without problems.

# apt-get upgrade Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]? y Setting up firefox (25.0.1+build1-0ubuntu0.13.04.1) ... update-alternatives: error: cannot stat file '/usr/lib/nx/nxserver': Too many levels of symbolic links dpkg: error processing firefox (--configure): subprocess installed post-installation script returned error exit status 2 Errors were encountered while processing: firefox E: Sub-process /usr/bin/dpkg returned an error code (1)

/usr/lib/nx/nxserver is NoMachine FreeNX which is similar to VNC, Remote Desktop.

# ls -l /usr/lib/nx total 20 lrwxrwxrwx 1 root root    17 Nov  5 09:44 nxserver -> /usr/bin/nxserver -rwxr-xr-x 1 root root 19441 Aug 12 10:45 nxsetup

# file /usr/bin/nxserver /usr/bin/nxserver: broken symbolic link to `/etc/alternatives/nxserver'

# file /etc/alternatives/nxserver /etc/alternatives/nxserver: broken symbolic link to `/usr/lib/nx/nxserver'

/usr/lib/nx/nxserver -> /usr/bin/nxserver -> /etc/alternatives/nxserver -> /usr/lib/nx/nxserver..

round and round ..

how about remove this file?

# rm /etc/alternatives/nxserver rm: remove symbolic link ‘/etc/alternatives/nxserver’? y

I was able to fix this, however I am not sure this way is appropriate or not.

# apt-get upgrade -y Reading package lists... Done Building dependency tree Reading state information... Done 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 1 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Setting up firefox (25.0.1+build1-0ubuntu0.13.04.1) ... Please restart all running instances of firefox, or you will experience problems. # echo $? 0