I've been trying to make an object's load function be called on lot load, but it doesn't work sometimes. In function's description (in SimPE) it says the function is called when "object version" variable is different from one in object's definition. I wonder, what the "object version" means, what it does, what makes it change, at what point, etc. Is it safe to change it manually (e.g. in expression) and what value can we change it to?

This may not be the answer you're looking for, but maybe it can help you get closer:

Have a look at this thread on object placement -http://modthesims.info/m/showthread.php?t=82685

Inge Jones and Dizzy have a side conversation going about the load function that may help.

Is there a particular reason why you want to use Function - Load for this, rather than Function - Init?

Ok, I didn't know it's only supposed to run, if object's code is changed. Thank you for the link, d4RE. I expected it to run on every single lot load, looking at maxis' use of this function. They have wall stereos turn on when sims arrive to community lot (= on lot load) in load function. Either I saw a leftover code that doesn't actually work, or there's something about community lots I don't know, or I misunderstand the meaning of "change of object on a disc", or there's more to it then people thought. I tend to trust people like Inge, so it's probably just me who doesn't get it.

I'll test my first assumption - to see if maxis' load function is what really makes stereos turn on on lot load.

I can get around it, it's not like the whole thing depends on load function, but I became really curious of how it works.

So, the load function really does run when you load a lot. I still don't know what the "object version" is, how and if it changes, but I've got my text notifications working on lot load and that's what I wanted (to notify players after lot is loaded about what happened last time they played this lot). The only thing is you can't put notifications or heavier stuff in the load function itself, you have to use it to nudge the main or other function to do what you want it to do. As of now, I know two ways - change object's attribute and have check for the change in main or set function on timer so it gets pushed later. Both work. (I use timer to push function that turns off stereos).