sed? - Insert line after a string with special characters to Neutron service

I am attempting to write a bash script that will insert a string after matching on a string in /usr/lib/systemd/system/neutron-server.service I have been able to do this on other files easily as I was just insert variables into neccessary config files, but this one seems to be giving me trouble. I believe the error is that sed is not ignoring the special characters. In my attempt I have tried using sed of single quotes and double quotes (which I understand are for variables, but thought it might change something. Is there a better way of going about this or some special sed flags or syntax I am missing? sed ‘/--config-file /etc/neutron/plugin.ini/a\--config-file /etc/neutron/plugins/ml2/ml2_conf_cisco_apic.ini‘ /usr/lib/systemd/system/neutron-server TL;DR - Insert --config-file /etc/neutron/plugins/ml2/ml2_conf_cisco_apic.ini After --config-file /etc/neutron/plugin.ini Orginial File [Unit] Description=OpenStack Neutron Server After=syslog.target network.target [Service] Type=notify User=neutron ExecStart=/usr/bin/neutron-server --config-file /usr/share/neutron/neutron- dist.conf --config-dir /usr/share/neutron/server --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugin.ini --config-dir /etc/neutron/conf.d/common --config-dir /etc/neutron/conf.d/neutron-server - -log-file /var/log/neutron/server.log PrivateTmp=true NotifyAccess=all KillMode=process TimeoutStartSec="infinity" [Install] WantedBy=multi-user.target File after desired change command. [Unit] Description=OpenStack Neutron Server After=syslog.target network.target [Service] Type=notify User=neutron ExecStart=/usr/bin/neutron-server --config-file /usr/share/neutron/neutron- dist.conf --config-dir /usr/share/neutron/server --config-file /etc/neutron/neutron.conf --config-file /etc/neutron/plugin.ini --config- file /etc/neutron/plugins/ml2/ml2_conf_cisco_apic.ini --config-dir /etc/neutron/conf.d/common --config-dir /etc/neutron/conf.d/neutron-server - -log-file /var/log/neutron/server.log PrivateTmp=true NotifyAccess=all KillMode=process TimeoutStartSec="infinity" [Install] WantedBy=multi-user.target