Current Issues with United Expert Mode
If you're a United elite member, there's a fairly good chance you're familiar with the airline's "Expert Mode," which lets you access fare class availability when searching on United.com. Expert Mode will return a flight's full availability broken out by fare class, so you can easily see if the flight you want has award or upgrade availability (whereas Expert Flyer can only display award availability for United and partner flights).
This takes the guess work out of whether or not an upgrade will clear — if you see any number other than 0 following "R" when searching with Expert Mode, you'll know it's possible to instantly upgrade your flight to business class (or two-cabin first class within the US). You can also see how many seats are available within a given revenue fare class (helpful if you're trying to find a flight with enough "cheap" seats for you and several companions).
While Expert Mode usually has some minor bugs that may impact results, such as inaccurate per-segment availability when you're searching for connecting flights, it typically functions quite well if you know how to work around its limitations. Unfortunately, for the past few weeks, Expert Mode has been much buggier than normal, making it very difficult to access fare-class information. Fortunately, there's a workaround, and United's PR team has confirmed that full operation will return soon.
The Expert Mode Workaround
As United works to fix this bug, it is still possible to pull up the regular fare class breakdown, albeit with another step. Rather than searching segment-by-segment, as you've probably done in the past, you'll need to add in a segment before the flight you're trying to find results for. So if you're looking for upgrade availability on EWR-LAX, as in the example above, you'll need to search [Airport 1]-EWR-LAX, instead.
So in the example above, I've added in an Albany to Newark segment at the beginning of the itinerary. I don't plan to book this flight as outlined above — I'm only interested in the Newark to Los Angeles segment (which happens to be operated by United's 777 for a limited time). Once I add Albany to the equation, Expert Mode springs into action for the EWR-LAX leg (results are notably absent for ALB-EWR). As you can see above, the flight is displaying R0, which means standard upgrades are not available. It does show PN9, however, so if you're a Global Services member, your upgrade will clear right away.
Until United fixes this bug, you'll need to add an additional segment to the beginning of your itinerary. Of course, once you confirm the fare class availability you're hoping to find, you can then complete your search as you actually intend to fly.
Have you found a better workaround for United's Expert Mode?