Need Help l25500 Substrate Jam on startup

[Kelcy Deeds]

Hey guys, anyone have any idea why i would get this error on startup? I just printed a job yesterday and i came back today and woke the printer up from sleep and it gave me that error. now on every startup, after it finishes initializing then it says substrate jam

 

[Bly]

Maybe the carriage rail needs lubing.

 

[Ian Stewart-Koster]

Is there something stuck under the carriage- a bit of torn vinyl or backing, for instance?