@Xebov
Logging out to the character select screen again and then back in or loading into a brand new zone will resolve group-related issues.
If the issue persists after re-logging, you can try reforming the group you were in when the issue occurred and then disbanding it. You can also try joining a large group and asking the group leader to disband it. This can help reset your UI.
DahliaNightshade wrote: »Old post, I know, but this happened to me and a friend of mine 2 days ago and it's still going on, we are stuck in this invisible group and we can no longer play anything which requires a group.