I don't want to create a flame war here, but some things need to be clarified.
Firstly, there were no invisible walls. Yes, there were some invisible gaps, but it has been said already here - drivers were aware of this and they knew that you have to avoid walls, and it's almost like that in real lifs. It was up to the drives either to push hard and risk with a DNF or go with a slower and more secure pace - Just like it has been always at Monaco. And still, the track was a lot wider, mod had more downforce and the track was in general more easy to drive than in last years.
Invisible gaps caused problems, but not quite much. Crashes always happen in Monaco. I looked at the results of last years WC race. In 2010 there were 16 DNF's (3 of them on 1st lap) out of 25 drivers (2 DQ's weren't under the DNF), it makes 64% of the drivers had to retire . In 2009 there were 15 DNF's (4 of them on 1st lap) out of 25 drivers, which makes it about 60%. And this year, there were 12 DNF's (5 of them on the 1st lap) out of 18 drivers, which makes it 66% of the drivers retired. So the percentage of DNF's has been similar past 3 years, it was a bit bigger this year, but there was a bigger 1st lap incident as well, which wasn't caused by track bug. I remember that only Atze crashed into the invisible gap in WC, and no offence, but it was his fault as he turned in too early.
Roualts crash was partly his fault - probably he was concentrating on other things rather than the wall. There was a little gap in the wall, where he crashed (
picture 1,
picture 2). There was a gap in 2009 in real life as well, but a little bit different -
picture. It was up to the drivers to be aware of that kind of gaps, as they are clearly visible. That gap there was more like a feature, not a bug.
As of how illegal this track is - Yes, this illegal and other such tracks have been used by SimBin for quite a time. But so has other leagues and racing club events here in Racedepartment used SimBin, NFS: Shift, F1 '10 tracks or other illegal tracks in leagues. Both GP4 and F1C tracks are legal to convert. GP4 tracks because the company went to bankrupt I think and Geoff said many-many years ago that it's ok to use GP4 work in other games. Converting F1C stuff is legal, because it's a ISI game as well, so in their own intrest it's legal.
To sum it up - Yes, there were bugs, but all of them couldn't be fixed in time due to some reasons. But then again, it wasn't that hard to avoid these walls. It seems some drivers were a bit spoilt by the amount of wallriding it was possible to do in last years, but wasn't this year. So I don't think the track was that much of a problem, it was Monaco and it has been always hard for many drivers, while some are in the world of their own in Monaco. For myself, driving was a lot easier than last year, maybe even too easy for Monaco.
The race was good to watch and congratulations to Bono, Fredrik and Patrick. Only too bad that Patrick had a problem in the pits, otherwise it would have end up like in real Monaco GP, where 3 drivers were fighting for the victory.
In the meantime Ondrej has made a post, and I must say that our views are quite same on this subject.