It looks like we can add UA to the "unbookable" airlines. I found some availability from EWR and IAD to Europe for early summer in what looks like F*. But when I tried a mock booking, the Aeroplan web site refused to book it.

*It was called Premium Economy, but the fare class was O and the necessary mileage was on F level

UA got rid of F and made O PY, similar to AC.

This issue on the Aeroplan site is known and has been discussed. This is not F space, and you should not be able to book it through Aeroplan. The only bug is that it's showing up at all.

I missed that discussion. Thanks for the info.

Yep. Just tried a few times today with a few different TAP routes. Aeroplan site showed availability, but couldn't complete booking on the site and over the phone.

Somewhere in this thread and elsewhere, are other posts asking the same about partner availability.

Short answer: the airlines do not release the same offerings to all *A partners. There are posts asking why UA and NH have awards that don't show on Aeroplan. On the SQ forum and NH forum, there are questions why awards don't match UA etc,

In your case it is about an earlier flight, in other examples, it is about partners and routes that don't show on Aeroplan.

Also, did you call Aeroplan and ask an agent if they see the space?

No.
All programs have similar issues. not just Aeroplan. Happens all the time with AA on Finnair availability for example.
It does not hurt to make a call to find out what the agent sees.

I think Aeroplan is not showing UA and NH availability properly, at least for some dates.
I tried searching for UA and NH biz/first class award space, but the Aeroplan website did not return any availability when I can see award space being available on other *A websites (UA, NH, AV, etc)
Even Expertflyer is saying there is positive award space at the saver level for UA and NH flights in biz/first class, but Aeroplan just doesn't display any.
Is anyone else having issues with UA and NH awards via Aeroplan?
I thought this was fixed some time ago but maybe not?

I booked UA I class 10 days ago.

LOT not bookable on Aeroplan
 

I've been trying to book a flight on LOT from BUD to WAW but only Austrian with a connection is available and timing doesn't quite work. Called Aeroplan, apparently no bookings work in LOT as after booking they were being cancelled by LOT. No expected resolution date. Was advised to just book a revenue ticket.

Dont hold your breath, last time it took months to fix.

Turkish Airlines not available
 

Any one else having issues with finding a TK flight? Last week I could find plenty of them from ORD and JFK to IST in August. Since yesterday I can't find any.

I can't remember if it was this thread (because I thought I had posted here but I guess I didn't!) or another thread, but I posted somewhere recently that this was an ongoing issue with LO and TK (and others), unfortunately. :(

How long does this outage usually last for? Just wondering if it is worth waiting out or trying to book another airline.