I just got infected with the 'Question Mark' walls for a second time, having read all the posts no-one seems to have yet come up with a solution so I decided to investigate the problem in a bit more depth myself and, although I have no idea what caused it or how to stop it happening again, I believe I have found a way to fix the corrupted lots - permanently (well, at least until the next time)
I was playing the 'Goth' lot when the game crashed whilst I was trying to access CAS via the 'Dresser' cheat, when I loaded the saved game most of my beautiful walls and floors were gone, I checked the 'Art Gallery' lot as it was this one that I had had problems with the first time I had 'Qustion Mark' disease and several of you mentioned this particular lot in your posts, I was not surprised to see that there was not a single wall or floor that hadn't been corrupted. I then checked the 'Wolf' lot which I hadn't played but was curious to see if it too had been given a new paint job after reading that this problem appears to only affect certain lots, sure enough, most of the exterior walls and several of the interior walls and floors were now a horrible shade of blue and red. After investigating all three lots I discovered the following problems:
1) The deign tool would no longer work on any wall or floor on the lot regardless of whether it had it's original pattern or the 'Qustion Mark' pattern
2) The eye-dropper tool did still work and not only could any remaining wall or floor designs on the lot be copied and pasted - so could the 'Qustion Mark' pattern (in case any-one out there REALLY likes it that much)
3) When selecting a pattern to copy with the eye-dropper the game should automatically highlight the appropriate thumbnail in the catalogue but this doesn't happen, in fact, it doesn't even show the right category anymore.
4) Although the eye-dropper tool will copy and paste any remaining patterns so you can cover up the 'Question Marks' it does not restore any functionality, the ?s have gone but the design tool will still not work.
5) If you use the eye-dropper tool to select a wall or floor which has had the pattern replaced by ? you will still get a tool tip telling you the name of the base pattern used (useful if you can't remember what was there before)
6) This problem affects every wall and floor on the lot, it makes no difference whether it is an unchanged base game design, your own unique concotion (saved or otherwise) or a download from the exchange.
7) As far as I could see only three lots are affected by the 'Question Mark' disease when it strikes:- Goth Manor, Lone Wolf Manor and Sunset Institute of Modern Art. (however I have not had time to check all lots yet)
8 The Sims 3 save game as well as its backup are affected and deleting cache files makes no difference at all, new games are not affected and nor are any other saved games
Fortunately the lots can be fixed but there is good news and there is bad news, first the good news:
If you are prepared to restore the lot to its original, unmodified, Maxis designed state, either because you haven't changed anything anyway or because you are more interested in saving the familly rather than their home then the fix is quick and fairly simple.
1) Start a new game and after selecting any familly EXCEPT Goth or Wolf go into 'Edit Town'
2) Click on either of the above families and in the pop up window select EVICT (option furthest to the left) leave belongings behind.
3) When the lot is empty click on it again and this time select SAVE COPY TO LIBRARY (just click OK on any warnings about interractions being cancelled)
4) Click on the evicted familly and get them to buy their house back again and then just do the whole thing again for the other familly
5) Save the Art Gallery the same way as the other lots (just no familly to evict first)
6) Click on options to return to MAIN MENU
7) Select your damaged game in the normal way and then go into EDIT TOWN
Change your active household if necessary and then EVICT the familly from the affected lot with or without furniture but make sure any irreplaceable rewards etc: are either in your Sims inventory or your household inventory
9) Demolish the affected lot with the 'Bulldozer tool' and then replace it with the saved one
10) Move the familly back into their new 'Question Mark' free house (repeat as necessary)
Now the bad news (and this is what I had to do)
If you have done a lot of customising of the lot and want to salvage as much as you can you are going to have to replace EVERY single wall and floor on the lot! If you just copy any of the original walls that are left and paste them over the ?s it won't work, as soon as you leave the lot or the game the ?s will return and probably in greater numbers!
1) Select the design tool and waft it over the lot to verify you need to do this, if buy and build mode objects 'light up' as you pass the tool over them but walls and floors don't then you're out of luck - read on!
2) Remember, do NOT copy any affected walls or floors with the eye-dropper, if they are not reacting to the design tool they are useless, instead, use the eye-dropper tool tip to identify the base game design used (not always obvious in-game if replaced by a ?)
3) Select the base wall or floor used from the relevant catalogue selection and paste it into the lot
4) Use any existing walls or floors as a guide to reproducing the design you want, don't forget that you may have customised objects in the room with elements from the wall or floor you are trying to recreate so use the design tool on the object and copy the pattern or colour back into your design
5) Once you have recreated your design on this new section of wall or floor then copy it with the eye-dropper tool and replace ALL the relevant sections on the lot, even if the original pattern hasn't been replaced by a ? it still needs to be replaced, and, just to rub salt in the wounds, you will have to pay for everything all over again, it's as if you are decorating bare walls!
6) When you think you have replaced all the corrupted areas use the design tool again to make sure you didn't miss any bits by repeating step '1' above. Waft the tool over the lot and you should now see that the replaced sections of wall or floor will 'Light up' as the tool passes over them, if you did miss a bit use the design tool first to make sure that the section you copy has been repaired.
I hope this will help some of you fix your games and also help someone much smarter than me to identify the cause of 'Question Mark' disease, by the way, I have the latest version of AM installed, my game is patched to 1.3 (still don't feel confident enough to re-install 1.4 after what it did to my game the first time) I have far too much custom content but can't seem to control my downloading addiction and my computer would be described as High End so, given that this problem has been encountered by others who don't use AM, have patched and unpatched games, no CC and numerous PC configurations, I think it must be something EA did - again!
Oh dear, this fix did work, but not for very long! Should have done a bit more play testing before posting. However I do have more information that may give someone more insight into what is causing this problem.
After replacing all of the corrupted walls and floors on the Goth lot I had no further problems and, in case the original save game had bad data, I did a 'Save as' and re-named it to something different so I got a completely seperate save game. When I re-started Sims 3 I loaded in this new saved game and the ?s were back! I re-installed the game and re-patched it to 1.3 in case any of the game files had been corrupted and tried again with the same saved game, the problem was still there so I deleted all of the wall and floor coverings that I could and replaced any floor tiles that I couldn't delete with an unmodified pattern from the catalogue, I then saved the lot to the library as both an occupied lot and as an empty lot.
I went back to the main menu and started a new game and I deleted the Goth lot and replaced it with my saved empty lot, there were no ?s this time but all of the new floors were again undesignable. I replaced all the floor and wall coverings for the third time and then saved the lot back to the library and moved the Goth family in, I noticed two single floor tiles with ?s but everything else was still OK so I replaced those and carried on playing without problems. After an hour or so I went to the main menu and checked out a couple of lots on an old Riverview save, then I went back to my earlier Sunset Vallry game only to find the Goth lot was once more covered in ?s.
I am going to try moving the Goth lot into a Riverview game to see if this makes any difference but I am beginning to suspect that this ? disease may be incurable once a lot is infected, sadly I may have to demolish the lot and the Goths will have to move in with the Crumplebottoms, they won't like that!