It's related to the Friend Stream in the HTC Sense UI. If you have Facebook or Twitter logins registered to the Friend Stream application this issue might happen. Remove the login information for both Facebook and/or Twitter from Friend Stream. Restart the device, go back into Friend Stream, register both Facebook and/or Twitter logins once again and the error should go away.
You can go to menu>settings>manage applications>running or all>scroll down to Friend Stream and clear the data/cache... it will clear all settings and info from the app so you can start over.