"you don't have access to that destination"

I just created an alt avatar. Made him a member of our group. But when I try to teleport to our private island the system tells me that it couldn't teleport him and that he doesn't have access to that destination. I've double checked the land to make sure that the group is set and that "Allow group access" is Checked. I checked my alt avatar to be sure that our group is his active group. But I'm stumped. Why wouldn't he be allow access?

Has he left the newbie orientation island for the mainland yet ??? If not then jump him out the Exit and then TP him.

I've found that if you TP to the region landing spot instead of a specific point, it will often let it go through. Like a lot of things in SL, I don't know if that was a one time thing or how things work most of the time. Nothing happens the same way ALL the time.

"You don't have access to that destination" indicates an estate access restriction.

Could be:
* Allow Public Access - checked
- banned (not sure if that's not a different message though)
- restricted on Payment Info
- restricted on Age Verification

* Allow Pubilc Access - unchecked
- the group isn't on the allowed groups list
(and) the avie's name isn't on the allowed users list
(If you're renting on that sim it could be that guests have to join/be invited to a common group before they have access to the sim)

(Related, if you ever get "No valid parcel found" that means the estate access permissions are allowing you in, but the parcel permissions aren't)

(Edited for clarification: when you're allowed on a sim but not on the parcel, it'll try to put you on a neighbouring parcel. If you're not allowed there it'll try to shift you onto another parcel and so on. If there's X parcels and you don't have access to all X of them then the tp fails; if you have access to 1 of the X but not the one you're tp'ing to then the tp succeeds and you'll end up on the parcel you do have access to)