Hi, I've had this problem recently in The Sims 2. I put my sim to cook and when my sim is finished cooking, the character resets and I lose the food I bought. When he manages to cook, then he can't eat and it resets again. It's causing me a lot of problems with the gaming experience.
I have the same issue!
I've been playing for 9 hrs and 35 mins with one household just fine, but now my sim can't eat food. He can eat cookies, but no food that is made.
It started happening after he tried to make Grandmas Comfort Soup, which would delete itself after cooking leaving the boiling sound running. (Which I fixed by cooking another meal that did not dissappear with the same sim)
But he could not eat it. He would go to the table, place the plate down and then try to sit. The animation of sitting down would reset once, after that he gave up.
Since he targeted one specific chair each time (I tried to have him eat several different dishes, did not fix it), I moved it away from the table. It did not help.
I moved the table itself, it did not help.
I bought a grill, a table and a chair in the garden and had him grill hotdogs. The hotdogs vanished.
I used the " boolprop testincheatsenabled true " cheat to force an error to reset him, it did not fix it. The only difference is that I now had the error message appear constantly.
I used the " moveobjects on " cheat combined with the one above to delete him in buymode, saved and went into the neighboorhood only to then go back to the household.
My sim was back, standing by the postbox. He ate one meal only to then have the same error messages return by simply standing still.
I've progressed a lot with this household and would love to be able to play more with them, but as it is now, it's pretty unplayable unless I choose to not have him there at all. Which I would rather not, I like having him there.
Edit: The meal he made after the soup was Spagetthi. Its very specific that he could not eat it, as he could put it away in the fridge. My other sim made a salad, I tried to have him eat that too but it did not work.
Edit 2: Repairing my game and updating it to the most recent update did not fix it.
