Firefox OS comes with a feature to synchronise ones contacts with Facebook. This is done through the Contacts → Settings → Facebook menus, and is documented at https://support.mozilla.org/en-US/kb/add-your-cont
However, when I do this, it asks me for a username and password, before giving me a (Facebook-side) error of "Invalid App ID: 323".
Probably related to bug #883344.
After reading the information provided about your issue I suggest a soft reset of the phone.
Please report back to us if this solved your problem!
Thank you for reaching out to Mozilla Support about your issue. After reviewing your issue, I recommend that you reach out to your place of purchase for more assistance.
Thanks for reporting this issue, I can reproduce it on my ZTE open also. I will investigate this more with the dev team, but I think your hunch about 883344 is a good one.
I am also having the problem. I can connect with facebook via the app and have imported contacts from gmail after trying the facebook importer. Michelle would you also drop me a note if you get an answer from support.