how can i solve this error ?

[mohamed saber]

Error evaluating 'OpenFcn' callback of World Frame block (mask) 'Final_light_assembly_URDF/World'. Callback string is 'simmechanics.sli.internal.block_dialog(gcbh,'open');'

Unable to write file /home/saber/.matlab/R2018b/matlabprefs.mat: permission denied.

[Walter Roberson]

! chmod u+rw /home/saber/.matlab/R2018b/matlabprefs.mat

If it says permission denied for that then possibly you are not the owner of the file. You might need to delete the file if you can, or get an administrator to delete it.

[mohamed saber]

I found the solution :

cd ~/.matlab

sudo chmod a+w -R R2018a/