A fare with a primary booking code of A or F carries a secondary booking code of C. It will book into C if A (or F) is not available - and it priced in A/F on at least one segment. This is supposed to be for the "inferior cabin" of a multi-cabin itinerary, but results in somewhat of an exploit on two cabin aircraft where C is frequently more available than A (usually D = A). C is a legacy artifact from when it was full fare Business.

And thus the law of unintended consequences (and a very poorly thought-through fare structure) results in the very deepest discount premium cabin fares now sometimes booking into C on a connecting itinerary (including on ps flights). Makes the SDC really really easy :)

FFox seems to be it for me, too. Asked web support and they do not acknowledge that it is a systematic issue. Annoying

I agree with the Firefox issues. Strangely another forum I am going to I am experiencing strange login/logout errors too.

Just ticketed an H class Y reservation SYD-SAN-SYD for flights next November. Went online to apply for upgrade to C using GPUs in my account but request upgrade function or option is nowhere on my reservation and unable to apply GPUs. I have 2 unused GPUs in my account and the ticket class is definitely compliant for GPU upgrade. Figured this might be an issue with new United.com and was hoping there might be a work around?

Were you logged in using Firefox? Try another browser and logging in there. I have had the oddest login issues with FF of late.

Yes, I was using FF, however, also used Safari and Chrome and same issue. So seems something wrong with the reservation information and I will have to give United a call to apply the upgrade request.

Has anyone else noticed that the ability to separate a passenger is no longer on the reservation page? I had to call last time (but I wanted to cancel one of the passengers so I had them do that as well) but I want to separate us on another reservation and still can't find it. Did it get moved or removed??

FFox must be it. Just received that message 4 times in the course of 2 flight searches in a few minute span. No issues in IE.

I've encountered this issue once or twice. I don't think it's been removed across the entire system and is only an intermittent issue. My guess is that it's a glitch with some reservations.

Not able to make any reservations on the website (explorer / firefox /chrome).
Tried the app (for an award search)...that too is not working.

So frustrating.

United booking search not showing miles
 

I am looking at booking a flight SIN<->SFO and even though I select the option to show mileage in the suggested flight details, all I see is '-' for al PQM,PQS,PQD on all flights.

what gives, is this broken?

Generally broken.

Today's flavour when trying to check in for a flight tomorrow:

"We could not process your request. Please see the message below and make revisions. error We could not process your request. Please see the message below and make revisions.
United is required to verify your travel document details for all international travel"

This is the same passport that has been on record for 9 years now and has been verified many a time.

Does your destination require a visa? That always triggers the unable to check-in error.