[Freesurfer] permission denied

Dear FreeSurfer users,

I am using freesurfer on 16 PCs (Ubuntu 14.04 64 bit). One of the PCs has the latest version of freesurfer 5.3.0 while the others have the version 5.0.0. The PC that is installed with the latest version freesurfer 5.3.0 does not allow me to run any command and everytime I try a command such such as tkmedit i get the following error /usr/local/freesurfer/bin/tkmedit: permission denied.

I have tried to change the permission settings sudo chown -R imaging:imaging freesurfer

but did not work.

Any ideas why is this happening although I have done the same thing to other PCs and they are working fine.

​Thanks in advance, Ali​