Yes, I've had this too! A quick close/reboot of the launcher seems to "cure" this every time.... but something has gone screwy methinks (the "Purchase" button is a luverly HUD "orange" though...makes you feel right at home)
I just had the same a few minutes ago, closed down launcher and re-opened it and now it's fine. Customer support reimbursed some credits I had lost earlier today, perhaps that may be the issue ??
It's an online game. When the launcher starts it checks with the server to see what you're entitled to. If there's a hiccup you get something you don't expect. I think this is called progress or modern gaming.
Happening to me also, sometimes I have to log out multiple times before I get the option to play. I wonder if it has anything to do with running 3 Elites at a time on one pc. 3 launchers & 3 installs of elite saved in different places. I do not use Steam to play Elite.
Seems to be an issue with steam launcher. Problem solved with a restart of the launcher. It's working fine since.
Never had that problem with frontier launcher alone before.