I actually liked having Strava post to facebook, but now I get an error every time I try to tell it to post a run I just completed to facebook. I might have to go into facebook's app settings and remove Strava and add it back, or to disconnect it inside Strava and reconnect it.

This is a recent change on Facebook's behalf - apps are no longer permitted to post automatically on your behalf [1]. I can understand why they've done it (searching for that reference involved going through 3 pages of "how do I stop app X from posting on Facebook") - but for those who actually wanted that feature, it will be missed.

1. http://uk.businessinsider.com/facebook-no-longer-lets-apps-a...