Unfortunately The Sims has lots of potential problems concerning custom content, some are caused by end-user error, some are caused by careless creators, some are caused by plain old bad luck.

Missing Expansion Packs:

My advice - if possible, try and install ALL the expansion packs (doesn't matter whether you use the Deluxe versions versus the individual EP's and the original Sims) - this will ensure wide support for custom objects as well as the greatest possible game stability.

Although I do try and investigate problems reported with objects I'm afraid it isn't always possible to know which objects require which expansion packs. Because I have all the EP's installed, it means new objects I create during the cloning process will include not only the information from the base object, but may also reference any changes made in later EP's to that object or even to a group of objects which the base object belongs to. Some changes are widely known, for instance, that Hot Date updated all existing sofas to add the cuddle function, anyone who has Hot Date installed can clone a sofa that comes with the original game and it will include the cuddle function, making it un-useable for anyone who does not have Hot Date.

Our labeling has improved greatly over the past couple of years thanks to visitor feedback, at this time I estimate it is probably 99% accurate, but if you have few EP's installed and you find an object is crashing your game, let me know what it is so I can investigate and update our labels accordingly.

GUID Clashes:

GUID Clashes are, in my opinion, the single biggest cause of The Sims crashing out. The problem is due in part to sloppy, irresponsible object creators, but also because the Magic Cookie system (designed to help prevent clashes) was never implemented in an organized fashion.

What is a GUID?

GUID = Global Unique Identifier. It is a bit like a product bar code, the 8 digit hexadecimal numbers inside each object need to be different to those used in every other object in order for the game to function properly, these help the game to remember where objects are placed, to tell it that certain objects are designed to work together cooperatively etc. 

How can I tell if I have an Object GUID clash?

The symptoms of an Object ID clash are one of the following: 

• Your game may crash when loading 

• It may crash when you click on a house in your neighbourhood view

• It may crash when you try and buy an affected object in build or buy mode

• Rarely you will find that an affected object will either not display an object correctly, for example you may find your 4 tile table only has 3 tiles visible, or the object takes on the appearance of its corresponding pair, for example your 2 tile painting is suddenly displayed as half painting, half bookcase 

• In rare cases you may find an object is entirely invisible when it is not supposed to be 

The latter two symptoms tend only to affect users with few EP's - the first two are much more common, especially for users with most or all of the Sims EPs.

How do I fix a GUID clash?

Sims Object ID program (look under 'Others' about halfway down the page) - this program will check for ID clashes and provide you with a fairly straightforward way to replace them (instructions are on the site). The major drawbacks of this program is it can't replace the ID's of some large items including beds - the solution obviously is to replace the ID of the other object in the pair. Remember to check the "Replace all occurrences" box as many items have references within the coding of the iff file which refer to the ID's. Choosing a number to replace the ID is entirely a matter of guesswork and you may have to run the check many times in order to establish that you have gotten rid of duplicated ID's completely. You can always remove an object which has a clash rather than correcting its ID. If you find clashes between objects and the middle digits of the GUID are 0000 then that means the creator didn't use a cookie at all, it may be advisable not to use their items in the future.

Sim Enhancer's Object Manager has an Object ID Check function as well as allowing you to categorize objects. This does have a 48 hour free trial which may be sufficient if having corrected existing clashes you intend only to download from a very limited number of sites whom you trust to use their Cookie's properly. Otherwise it is $9.95 - I believe there are various methods of payment available so a credit card isn't necessarily required, I would strongly recommend that you try and purchase this highly useful program if you download a lot as its fairly quick to check ID's and will check your suggested replacement number there and then and ask you to choose another if that ID is already in use. Simply hit the Object ID check button in the top left corner to run a check on your installed objects.

Bunny's "The Sims" page provides a utility called Thing Check, it is free to download and it checks both object ID's and Object integrity - it is however only supported up to House Party - I have no idea if it works with later expansions. Instructions are provided on the developer's website.

How can I prevent GUID clashes?

My advice is before you download items check with the site you wish to download objects from, ask if the object creator uses a Magic Cookie AND if so do they make sure all their previously cloned & published objects are in their game folders when they clone. If the answer is no or 'um...?' then I would suggest don't download their work until you are confident about regularly checking your game's ID's. There is unfortunately, nothing creators like myself, who do use our Cookies properly, can do about the creators who do not - many of us still creating get blamed on a regular basis for problems resulting from objects made, in some cases many years ago by creators long gone from the Sims - the clash of course isn't triggered until the second item in the matching pair is introduced into the game.

Are there times when it is not a good idea to change the GUID of an object?

Some objects you have installed may be carefully edited to work with other objects - if you change their ID you will undo the editing and the objects wont work as expected. Objects that have NPCs attached are a prime example, its something that can only really be checked if the creator has labeled their objects helpfully, for example if you find that bluevase.iff clashes with redcashregister.iff then change the ID of bluevase.iff in preference in case the redcashregister.iff has a corresponding redcashier.iff NPC that goes with it! If the two files in question are called tmoggedobject578906.iff and tmoggedobject046922.iff then obviously you might as well flip a coin for all the sense you'll make out of the filenames - I would recommend getting yourself a copy of an object viewer tool such as SimExplorer to find out what files such as those actually are before you edit their ID's.

There are various controller files as well aside from NPCs that are also specifically told by the creator they should reference the ID's of another object and vice versa, for example our Bars all have bar controller files in addition to the bar NPCs - these all link into each other, if the ID of one part is changed then the whole thing ceases to work. If you find items like that in your clashing pairs then try to pick the 'ordinary' object to correct in preference, all regular objects like counters, tables, chairs, beds etc can have their ID's replaced fine with no issue (Object ID users remember that Replace all occurrences check box!). 

Remember if in doubt you can always move objects you are concerned about out of your directory and check which items belong together, it may be that the redcashregister.iff doesn't come with an NPC at all in which case its ok to change its ID. Such items include all NPCs in conjunction with most of the following - Cash registers, Food & Drink carts plus the food or drink controller file, restaurant Podiums and Bars (not the single tile home use bar!), pet displays, DJ Booth, dance floor plus controller, Fashion Runway, Photo Shoot Set, Recording Studio, Vacation Check-In Desk, Massage Table, Lot Controller files (rare!) etc - there are others but these are a sample of some of the ones that we have on the site here.

Generally there aren't a huge number of sites that have ever bothered with such editing but its something to be aware of when you are correcting ID duplications.