I'm not sure if I messed this up or not, but I have an Evo 3D & I noticed just after I loaded the facebook app, I had (both) a facebook app and an HTC sense app for facebook. At first, all my friends' birthdays showed up on my phone's calendar but I started getting a sync error on the HTC sense app where the directory for sync is. I thought I'd solve the problem by deleting the HTC sense app, but it didn't solve anything. First question is, can I reload the HTC sense app? I didn't see it in the market so I'm assuming it's a factory installed app. Finally, I've gone through all my sync settings, and all the right things are checked in the app and on my calendar. Any more suggestions as to how I can resolve my sync problem? Thanks!

Facebook for HTC Sense is not an actual application, but it is a set of features build into the user interface. They allow you to synchronize facebook contacts with your phonebook, link the camera with facebook, etc)
To fix the sync problem check the settingss under Menu-->Settings-->Accounts-->Sync, click on Facebook for HTC Sense and verify that Sync Contacts option is checked.
When this is done, go into your contacts, tap menu-->view and make sure Facebook for HTC Sense option is checked.

Actually, part of my problem was I thought I deleted HTC sense, but I found a thread in another forum with a similar problem. Thanks for your reply as well! I'm going to post what I did to help others that may have had a similar problem: go to Settings, Accounts & sync, then tap on the "add account" button at the bottom of the screen & facebook for HTC sense will be on the next screen. I added it back in there. Thanks again for your reply.

I have a similar problem...but Facebook for HTC Sense is no long listed under Accounts & Sync or Add an Account? How do I get it back?

Everything went wrong after a system upgrade pushed to my phone. I am running Android 2.3.6. HTC Sense Version 3.5. Software number 2.18.1010.8. I do live in Korea so I don't use Sprint for a carrier. Thanks...MAH