Why do we generally not do as well in Europe, even under Fergie?

It's worth noting that in the first decade Fergie was manager, European football was very different. Finishing 2nd in the league didn't even get you into the competition until 1997. English teams were still miles behind the European teams for most of the 1990s due to the long term impact of the post Heysel ban.

In the last 16 years of Fergie's reign that the Champions League started to resemble its current format, we got to 4 finals (winning two), 3 additional semi finals (97, 02, 07) and were only knocked out the Group Stage twice.

He was also perhaps unlucky that his last two finals came against arguably the best club side ever. We were very close to another final against a Chelsea side in 2009 that we'd beaten comfortably a few months earlier and would have been strong favourites to win again.
 
1993-1996 - The three foreigner rule hindered our chances as we couldn't field our strongest teams in Europe. Scots, Irish, Welsh were considered foreign and we had a fair few of them.

1996-1997 - We had the best goalkepper and arguably the best midfield in Europe, what we lacked that season was a world class number nine. Evident to see in those semi final games against Dortmund when we could hit a barn door...Cantona was out of sorts and on the decline and Cole after a difficult first two years was only just starting to bloom. A Shearer or Batistuta in that team and we would've been in the final.

1997 - 1998 - No Keane for the season but we still smashed the group stage playing the best football in Europe. However when the Quarter Finals came round in Spring we were hit with a lot of injuries to key players and the strikers were off form. The squad lacked quality in depth.

1998-1999 - Won

1999-2000 - We had the best midfield in Europe and a collection of top strikers but had glaring weaknesses at the back. IMO we didn't replace Schmeichel well enough and lacked a serious partner for Stam in defence. Johnsen and Brown's seasons' were wiped out by ACL injuries, new young defender Silvestre was terrible and Berg was on the decline.

The Quarter final first leg against Madrid at the Bernabeu ended 0-0. Bosnich had a good game and we were robbed a goal/penalty and sending off. Centre-back Karanka tipped an Andy Cole header over the bar!

The second leg affair was exhilarating. It was also the night I think Fergie's gung-ho approach had been found out. Tactically Madrid had the upper hand by overloading the midfield leaving Keane and Scholes too much to do and vunerable on the counter attack. We still created a ton of chances and if it wasnt for 18yrs old Cassilas MOTM performance we would've won the tie.
 
Several great points in this thread. Up until around 2002, we couldn’t compete financially with the Serie A and La Liga clubs. The Prem simply wasn’t generating as much money as it was today. I think Sir Alex himself once said that the priority for United every season is the league. This is, of course, a difference in mentality to Real Madrid that prioritises the Champions League.

We had a relatively low wage ceiling we couldn't compete in wages with the big clubs in Italy and Spain in the 90s

At United the highest earners were Eric Cantona and Schmeichel on around 30k a week. You had the likes of Batistuta on 50-60k a week in Fiorentina. We had no chance in buying the best players in their prime to help us dominate Europe unless we broke the wage structure.

In Fergie's Autobiography Managing My Life (1999) He wrote

"I have been severely handicapped by the club's insistence on a wage ceiling at Old Trafford"...

"In recent years I have been keen to sign Ronaldo, Batistuta and Marcel Desailly but my hands were tied because Manchester United's policy on salaries gave me no chance of providing the financial package required to secure those great player's contracts.

I think the restrictions applied to wages prevented us from being the power in European football that we could have been in the nineties. Becoming a PLC has naturally affected all areas of the club's life and whenever money is involved certain procedures have to be followed and strict limitations are in force..."
 
I do not think we underachieved under Ferguson. The Champions League is a hard competition to win. We did really well in the competition between 06-11. Sure, we could have been a bit better in the years following the treble, but that is about it.

What I do think is that even when we had the best team in Europe, like in 07-08, we didn't dominate games as we should and could have done. But I guess that was something that was sacrificed in order to get better results.
 
Fergie always said he thought he should have won more in Europe but was never clear on why we didn't!

I always put it down to the fact that our domestic league competitions, i.e. both pre and post PL, were always more demanding, energy sapping, and for a long time more important to our supporters etc. than the majority of the 'competitive elements' that were present in the top leagues in other European countries. The style of football was different in the UK than most other European leagues, more frenetic, this tended to 'blunt our edge' in European competitions, until managers such as Paisley and Fergie, found 'a way to win' in Europe.
 
What club apart from Real (and they've had their lean years, I remember) has not underperformed in Europe? Almost every top club I can think of can claim this:

Barcelona
Juventus
Bayern
City
Chelsea

Maybe there's a running theme here beyond Ferguson's perceived failings?
 
Too much plucky underdog counter attack set up. Fergie was guilty of it as well.

We usually didnt have the players or the tactical nous to beat Barca, Real, Bayerns at their own game.

In 2008 we beat Barca with 3 shots and averaged 32% possession over the two legs.
 
Because hes a mythical manager who was always expected to perform miracles. When Fergie had the best squad in europe he won the thing. And when he didnt, it should be understandable to not win it.

What happened after Fergie shouldnt be mentioned. We were bad in all comps not only europe.
Fergie never had the best squad in Europe though, and there you have it.
 
Too much plucky underdog counter attack set up. Fergie was guilty of it as well.

We usually didnt have the players or the tactical nous to beat Barca, Real, Bayerns at their own game.

In 2008 we beat Barca with 3 shots and averaged 32% possession over the two legs.
All that possession and hardly had a shot United missed a penalty at the nou camp and scored at home that’s why they please don’t rubbish us on a united site
 
Apart from the good things said in several posts, we were/are crap at the dark arts. Our fouls look clumsy and late and English media has a strong dislike to diving inside and outside the box. Divers are named, shamed and targetted.
European teams and media don't really care about all that. They would do every small thing to gain advantage and break up the play. Though there may not be a direct correlation in every game, it helps a lot in disturbing the tactics of the team.