Jerry's got a point. If the coach isn't in Travel Mode when the slides are operated, there can be body twist that results in your trying to put a square slideout through an unsquare opening. Things can get hung up. Unlike some other coach mfrs., Monaco's basic rule was slides out first and in last; i.e. the rig should be aired to Travel when moving slides.
Barring that, some with "locks" on that slideout have had issues with broken internal parts, which makes it a good idea to have BCS or other experienced tech inspect the two mechanisms every few years. Perhaps someone that has had that issue will provide input here.
Joel