I found exactly the same when attempting to OLCI for HKG about 2 weeks ago. I exited the browser and immediately tried again and this time the normal screen appeared and I was able to check in.

Then the same thing happened on the return leg, too, first time same message as above, second time normal OLCI.

There may have been something different I did on the two occasions, but if there was, I couldn't work out what it was. (I probably tried both IE and Firefox on the way out, but I was at the mercy of a hotel's browser on the way back so had no choice).

Good luck trying again, I hope that's all it takes.