If for any reason the carriage runs into an end plate you can perform a hard reset. On the inner side of Home (Power button side) you will see two small buttons, The one closes to the power button is the hard reset.
If a hard reset doesn't resolve the issue, update firmware and reconfigure the slider. Please see the Firmware/Configuration article for more information.
If you are still experiencing problems, reach out to firstname.lastname@example.org and we will be happy to assist you.