I fixed it! I did not realize I needed to go to admin folder ->then in templates and then put the symbolic link there
$> /opt/webwork/courses/admin/templates
then
ln -s /opt/webwork/libraries/webwork-open-problem-library/OpenProblemLibrary Library
$> /opt/webwork/courses/admin/templates
then
ln -s /opt/webwork/libraries/webwork-open-problem-library/OpenProblemLibrary Library