If you decide to enable System Integrity Protection again, now follow the next guide.
Please Note that, if you enable System Integrity Protection, you can't use M4V Converter Plus any more.
You must boot into the Recovery OS. You do this by restarting your machine, and holding COMMAND + R until the Apple logo appears, Then select Terminal from the Utilities menu.
In the window that opens, type csrutil clear and press return.
This clears existing configuration of System Integrity Protection to default state which is "enabled".
Now type reboot and press return to restart your machine.
If you have some other problems, please contact our Support Team at support@m4vconverterplus.com to get assistance.